Patient remote and associated methods of use with a nerve stimulation system

ABSTRACT

A neurostimulation system having an external or an implantable pulse generator programmed to innervate a specific nerve or group of nerves in a patient through an electrode as a mode of treatment, having a patient remote that wirelessly communicates with the pulse generator to increase stimulation, decrease stimulation, and provide indications to a patient regarding the status of the neurostimulation system. The patient remote can allow for adjustment of stimulation power within a clinically effective range and for turning on and turning off the pulse generator. The patient remote and neurostimulation system can also store a stimulation level when the pulse generator is turned off and automatically restore the pulse generator to the stored stimulation level when the pulse generator is turned on.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application claims the benefit of priority to U.S.Provisional Patent Application No. 62/101,666, filed on Jan. 9, 2015,entitled “Patient Remote And Associated Methods Of Use With A NerveStimulation System,” which is herein incorporated by reference in itsentirety for all purposes.

The present application is related to U.S. Provisional PatentApplication Nos. 62/038,122 filed on Aug. 15, 2014 and entitled “Devicesand Methods for Anchoring of Neurostimulation Leads”; 62/038,131, filedon Aug. 15, 2014 and entitled “External Pulse Generator Device andAssociated Methods for Trial Nerve Stimulation”; 62/041,611, filed onAug. 25, 2014 and entitled “Electromyographic Lead Positioning andStimulation Titration in a Nerve Stimulation System for Treatment ofOveractive Bladder, Pain and Other Indicators”; and concurrently filedU.S. Provisional Patent Application Nos. 62/101,888, entitled“Electromyographic Lead Positioning and Stimulation Titration in a NerveStimulation System for Treatment of Overactive Bladder;” 62/101,899,entitled “Integrated Electromyographic Clinician Programmer For Use Withan Implantable Neurostimulator;” 62/101,897, entitled “Systems andMethods for Neurostimulation Electrode Configurations Based on NeuralLocalization;” 62/101,884, entitled “Attachment Devices and AssociatedMethods of Use With a Nerve Stimulation Charging Device;” and62/101,782, entitled “Improved Antenna and Methods of Use For anImplantable Nerve Stimulator;” each of which is assigned to the sameassignee and incorporated herein by reference in its entirety for allpurposes.

FIELD OF THE INVENTION

The present invention relates to neurostimulation treatment systems andassociated devices, as well as methods of treatment, implantation andconfiguration of such treatment systems.

BACKGROUND OF THE INVENTION

Treatments with implantable neurostimulation systems have becomeincreasingly common in recent years. While such systems have shownpromise in treating a number of conditions, effectiveness of treatmentmay vary considerably between patients. A number of factors may lead tothe very different outcomes that patients experience, and viability oftreatment can be difficult to determine before implantation. Forexample, stimulation systems often make use of an array of electrodes totreat one or more target nerve structures. The electrodes are oftenmounted together on a multi-electrode lead, and the lead implanted intissue of the patient at a position that is intended to result inelectrical coupling of the electrode to the target nerve structure,typically with at least a portion of the coupling being provided viaintermediate tissues. Other approaches may also be employed, forexample, with one or more electrodes attached to the skin overlying thetarget nerve structures, implanted in cuffs around a target nerve, orthe like. Regardless, the physician will typically seek to establish anappropriate treatment protocol by varying the electrical stimulationthat is applied to the electrodes.

Current stimulation electrode placement/implantation techniques andknown treatment setting techniques suffer from significantdisadvantages. The nerve tissue structures of different patients can bequite different, with the locations and branching of nerves that performspecific functions and/or enervate specific organs being challenging toaccurately predict or identify. The electrical properties of the tissuestructures surrounding a target nerve structure may also be quitedifferent among different patients, and the neural response tostimulation may be markedly dissimilar, with an electrical stimulationpulse pattern, frequency, and/or voltage that is effective to affect abody function for one patent potentially may impose significant pain on,or have limited effect for, another patient. Even in patients whereimplantation of a neurostimulation system provides effective treatment,frequent adjustments and changes to the stimulation protocol are oftenrequired before a suitable treatment program can be determined, ofteninvolving repeated office visits and significant discomfort for thepatient before efficacy is achieved. While a number of complex andsophisticated lead structures and stimulation setting protocols havebeen implemented to seek to overcome these challenges, the variabilityin lead placement results, the clinician time to establish suitablestimulation signals, and the discomfort (and in cases the significantpain) that is imposed on the patient remain less than ideal. Inaddition, the lifetime and battery life of such devices is relativelyshort, such that implanted systems are routinely replaced every fewyears, which requires additional surgeries, patient discomfort, andsignificant costs to healthcare systems.

Furthermore, not all adjustments to neural stimulation systems have beenimplemented by clinicians. Patient devices can adjust stimulation or toturn off the neurostimulation system. Unfortunately, the wide variety ofadjustments that can be made have the potential to confuse patientsand/or eventually result in a significant reduction in long-termefficacy of these systems.

The tremendous benefits of these neural stimulation therapies have notyet been realized. Therefore, it is desirable to provide improvedneurostimulation methods, systems and devices, as well as methods forimplanting and configuring such neurostimulation systems for aparticular patient or condition being treated. It would be particularlyhelpful to provide such systems and methods so as to improve ease of useby the physician in implanting and configuring the system, as well as toimprove patient comfort and alleviation of symptoms for the patient. Itwould also be helpful to provide systems and methods to allow thepatient to adjust the stimulation level delivered by suchneurostimulation systems, where such adjustment is simple, unambiguous,and sufficiently limited to ensure the stimulation can remain within aclinically effective range.

BRIEF SUMMARY OF THE INVENTION

A patient remote is provided to allow a patient to adjust thestimulation level of a neurostimulation system, which can include anelectrical pulse generator coupled to an implanted electrical lead. Thedegree of adjustment permitted to the patient through the patient remotecan be limited, such that while the patient can incrementally increaseor decrease the therapy delivered by the neurostimulation system, sothat the level of stimulation therapy by the neurostimulation system ismaintained within a clinically effective range. By providing acontrolled and limited range of adjustment to a patient through thepatient remote, the patient is given a straightforward and simple toolfor operation of the neurostimulation system, without presenting aselection of therapy or operational programs that may unnecessarilyconfuse a patient or take the neurostimulation system outside of theclinically effective range. The clinically effective range of theneurostimulation system can be determined by a physician or theclinician programmer when setting the parameters of the neurostimulationsystem. The patient remote can also allow a patient to turn off theneurostimulation system, which may be desirable for the patient whenperforming activities that may inadvertently interfere with, or beinadvertently interfered by, the neurostimulation system and the nervesstimulated by the neurostimulation system.

In some embodiments a patient remote according to the present disclosureis configured to wirelessly control a nerve-stimulating pulse generatorcoupled to an implantable lead in a patient, where the patient remoteincludes: a portable housing configured to be operable in a single handof an operator. Circuitry may be at least partially disposed within theportable housing, and an activation switch can be on an exterior surfaceof the portable housing and coupled with the circuitry to reconfigure ortransition the patient remote between an awake mode and an asleep mode.A stimulation-increase switch can be disposed on the exterior surface ofthe portable housing and coupled to the circuitry so as to wirelesslyincrease a stimulation level of the pulse generator when the patientremote is in the awake mode. Actuation of the stimulation-increaseswitch for a first period of time may increase the stimulation level(including by turn stimulation on stimulation if the pulse generator waspreviously off). Actuation of the stimulation-increase switch for asecond period of time may restore the stimulation level of the pulsegenerator to a previously stored or last stored stimulation level (andmay also turn stimulation on). The first period of time and the secondperiod of time can be demarked by a threshold time. In some aspects,actuation of the stimulation-increase switch for the second period oftime ramps the stimulation level to the previously stored or last storedstimulation level. As described in any of the embodiments herein,previously stored stimulation level can refer to a last storedstimulation level.

In other aspects, the patient remote can further include astimulation-decrease switch disposed on the exterior surface of theportable housing configured to wirelessly decrease the stimulation levelof the pulse generator, where when the activation switch of the patientremote is in the awake mode, actuation of the stimulation-decreaseswitch for the first period of time decreases the stimulation level orturns off stimulation of the pulse generator, and where actuation of thestimulation-decrease switch for the second period of time stores thestimulation level in a memory element and turns off the stimulation bythe pulse generator. In further aspects, actuation of thestimulation-increase switch incrementally increases the stimulationlevel up to three or four stimulation levels above a baseline or nominalstimulation level and actuation of the stimulation-decrease switchincrementally decreases the stimulation level down respectively to threeor two stimulation levels below the baseline stimulation level. Asdescribed herein, a baseline or nominal stimulation level can be theoptimum stimulation level, which can be determined by the CP or can beset by the clinician. In some aspects, this nominal stimulation levelcan be determined based on sensory or motor responses, qualitativesensory feedback or various combinations thereof. In some embodiments,determination of the nominal stimulation level can be based in part on athreshold level of the selected electrodes and a maximum stimulationlevel based on patient comfort. In some embodiments, the nominalstimulation can be determined so that incremental adjustment ofstimulation levels by the patient in either direction remains within aclinically effective range. In some aspects, each stimulation levelincrease or stimulation level decrease of the pulse generator comprisesmore than five percent (5%), optionally at least ten percent (10%) of anominal stimulation level or a current stimulation level.

In many embodiments, the patient remote can further include astimulation-level display disposed on the exterior surface of theportable housing. The patient remote may be configured to wirelesslycommunicate with the pulse generator and the stimulation-level displaymay be configured to indicate a current stimulation level of the pulsegenerator when the activation switch of the patient remote is switchedfrom the asleep mode to the awake mode. In some aspects, thestimulation-level display can include a plurality of light emittingdiodes, where a number of illuminated light emitting diodes indicatesthe current stimulation level of the pulse generator. In other aspects,the stimulation-level display can include at least seven light emittingdiodes of at least two, three or four sizes, where a baselinestimulation level can be indicated by illumination of (for example) thefirst three or four light emitting diodes.

In further aspects, the patient remote can also include atherapy-remaining display disposed on the exterior surface of theportable housing, and can be configured to indicate therapy remainingstatus based on at least a charge or voltage remaining in a battery ofthe pulse generator and stimulation use parameters by the patient. Insuch aspects, the therapy-remaining display can include a light emittingdiode having at least two contrasting colors or a single color withflashing and non-flashing modes or both to indicate if the pulsegenerator needs re-charging, is charging, or has sufficient charge forat least four days of nominal stimulation. In particular aspects, thetherapy-remaining display light emitting diode can illuminate with anon-flashing green color to indicate at least four (4) days of therapyremaining, can illuminate with a non-flashing amber color to indicatetwo to four (2-4) days of therapy remaining, and can illuminate with aflashing amber color to indicate less than two (2) days of therapyremaining. In some aspects, the patient remote can further include anautomatic fault condition indicator disposed on the exterior surface ofthe portable housing that is configured to provide an alert if the pulsegenerator is in a fault condition. In other aspects, the patient remotecan further include a haptic indicator coupled to the portable housingthat is configured to vibrate when a command from the patient remote hasbeen executed by the pulse generator. In further aspects, thenerve-stimulating pulse generator can include an external or implantablepulse generator, and the implantable lead comprises at least oneelectrode configured for insertion into a foramen of a sacrum near asacral nerve.

In other embodiments, a patient remote is configured to wirelesslycontrol a nerve-stimulating pulse generator coupled to an implantablelead, the patient remote having: a portable housing configured to beoperable in a single hand of an operator and circuitry at leastpartially disposed within the housing; an activation switch disposedwithin a recessed area of the portable housing so as to allowreconfiguration or transition between an awake mode and an asleep mode;a stimulation-increase switch disposed on an exterior surface of theportable housing, configured to wirelessly increase a stimulation levelof the pulse generator; and a stimulation-decrease switch disposed onthe exterior surface of the portable housing, configured to wirelesslydecrease a stimulation level of the pulse generator; where when therecessed activation switch of the patient remote is in the asleep mode,the stimulation-increase switch and the stimulation-decrease switch areinactivated, and where when the recessed activation switch of thepatient remote is in the awake mode, the patient remote is configured towirelessly communicate with the pulse generator. In some aspects, thestimulation-increase switch and the stimulation-decrease switch are eachdisposed on a raised region of the exterior surface of the portablehousing, where the stimulation-increase switch can further have atactile feature that is larger in size than that of thestimulation-decrease switch. In other aspects, actuation of thestimulation-increase switch can incrementally increase the stimulationlevel up to three or four stimulation levels above a baselinestimulation level, and actuation of the stimulation-decrease switch canincrementally decrease the stimulation level down respectively to threeor two stimulation levels below the baseline stimulation level. Infurther aspects, each stimulation level increase or stimulation leveldecrease of the pulse generator can be at least ten percent of abaseline stimulation level or a current stimulation level.

In some embodiments, the patient remote can further include astimulation-level display disposed on the exterior surface of theportable housing, where the patient remote is configured to wirelesslycommunicate with the pulse generator and the stimulation-level displayis configured to indicate a current stimulation level of the pulsegenerator, when the activation switch of the patient remote is switchedfrom the asleep mode to the awake mode. In some aspects, thestimulation-level display can include a plurality of light emittingdiodes, where a number of illuminated light emitting diodes indicatesthe current stimulation level of the pulse generator. In particularaspects, the stimulation-level display can include at least seven lightemitting diodes of at least three or four sizes, where a baselinestimulation level can be indicated illumination of the first three orfour light emitting diodes. In other aspects, the patient remote canfurther include a therapy-remaining display disposed on the exteriorsurface of the portable housing configured to indicate therapy remainingbased on at least a charge of voltage remaining in a batter of the pulsegenerator a stimulation use parameters by the patient. In furtheraspects, the therapy-remaining display can include a light emittingdiode having at least two contrasting colors or a single color withflashing and non-flashing modes to indicate if the pulse generator needsre-charging, is charging, or has sufficient charge for at least fourdays of nominal stimulation. In such aspects, the therapy-remainingdisplay light emitting diode can illuminate with a non-flashing greencolor to indicate at least four (4) days of therapy remaining, canilluminate with a non-flashing amber color to indicate two to four (2-4)days of therapy remaining, and can illuminate with a flashing ambercolor to indicate less than two (2) days of therapy remaining. In someaspects, the patient remote can further have an automatic faultcondition indicator disposed on the exterior surface of the portablehousing configured to provide an alert if the pulse generator is in afault condition. In other aspects, the patient remote can further have ahaptic indicator coupled to the portable housing configured to vibratewhen a command from the patient remote has been executed by the pulsegenerator.

In further embodiments, the present disclosure is directed to a methodfor controlling a nerve-stimulating pulse generator coupled to animplantable lead within a patient with a patient remote, the methodincluding: wirelessly communicating with the pulse generator after anactivation switch of the patient remote reconfigures or transitions thepatient remote from an asleep mode to an awake mode; displaying acurrent stimulation setting of the pulse generator on astimulation-level display of the patient remote; and wirelesslyincreasing a stimulation level or turning on stimulation of the pulsegenerator when a stimulation-increase switch of the patient remote isactuated for a first period of time or turning on and restoringstimulation of the pulse generator to a previously stored stimulationlevel when the stimulation-increase switch of the patient remote isactuated for a second period of time. In some aspects, the method caninclude wirelessly decreasing the stimulation level or turning offstimulation of the pulse generator when a stimulation-decrease switch ofthe patient remote is actuated for the first period of time or storingthe stimulation level and turning off stimulation of the pulse generatorwhen the stimulation-decrease switch of the patient remote is actuatedfor the second period of time. In other aspects, the method can furtherinclude automatically switching the patient remote from the awake modeto the asleep mode after a period of patient remote inactivity, whereinthe period of inactivity comprises at least ten (10) seconds. In furtheraspects, the method can also include deactivating thestimulation-increase switch and stimulation-decrease switch of thepatient remote when the activation switch of the patient remote is inthe asleep mode. In yet further aspects, the method can includedisplaying a status of therapy remaining in the pulse generator on thepatient remote, where the therapy remaining status is based on at leasta charge or voltage remaining in a battery of the pulse generator andstimulation use parameters by the patient.

In some embodiments, the present disclosure is directed to a method forcontrolling a nerve-stimulating pulse generator coupled to animplantable lead within a patient with a patient remote, the method atleast including actuating an activation switch to switch a patientremote between an awake mode and an asleep mode, where when the patientremote in the awake mode: actuating a stimulation-increase switch for afirst period of time to turn on or incrementally increase thestimulation level of the pulse generator or actuating thestimulation-increase switch for a second period of time to turning onand restoring stimulation of the pulse generator to a previously storedstimulation level; and actuating a stimulation-decrease switch for thefirst period of time to turn off or incrementally decrease thestimulation level of the pulse generator or actuating thestimulation-decrease switch for the second period of time to store thecurrent stimulation level and turn off stimulation of the pulsegenerator.

In other embodiments, the present disclosure is directed to animplantable nerve stimulation system having an implantableneurostimulator and a portable patient remote configured to wirelesslycontrol the implantable neurostimulator, where the portable patientremote can include: an external housing having an oblong or rectangularshape; a stimulation-increase switch disposed on an exterior surface ofthe portable housing configured to wirelessly increase a stimulationlevel of the implantable neurostimulator; a stimulation-decrease switchdisposed on the exterior surface of the portable housing configured towirelessly decrease a stimulation level of the implantableneurostimulator; and a recessed activation switch disposed on theexternal housing and having an awake mode and an asleep mode, where whenthe recessed activation switch of the patient remote is in the asleepmode, the stimulation-increase switch and the stimulation-decreaseswitch are inactivated, and where when the recessed activation switch ofthe patient remote is in the awake mode, the patient remote isconfigured to wirelessly communicate with the implantableneurostimulator and actuation of the stimulation-increase switch for afirst period of time increases the stimulation level or turns onstimulation of the implantable neurostimulator while actuation of thestimulation-increase switch for a second period of time turns onstimulation of the implantable neurostimulator and restores thestimulation level of the implantable neurostimulator to a previouslystored stimulation level.

In further embodiments, the present disclosure is directed to a systemfor treating a patient with a disorder associated with a nerve, wherethe system includes a nerve-stimulating pulse generator having wirelesscommunication circuitry and a plurality of stimulation levels; animplantable lead configured to be coupled with the pulse generator andimplanted in the patient in operative communication with the nerve; anda patient remote. In such embodiments, the patent remote can include: aportable housing configured to be carried daily by the patient;circuitry disposed within the portable housing, the circuitry configuredto wirelessly communicate with the wireless communication circuitry ofthe pulse generator; and a stimulation level varying switch disposed onthe portable housing, the stimulation level switch coupled to thecircuitry so as to wirelessly alter an applied stimulation level of thepulse generator when the switch is actuated, the applied stimulationlevel being selected from among the plurality of stimulation levels ofthe pulse generator so that actuation of the stimulation level switchallows the patient to select a level of stimulation being applied by thepulse generator to the lead; where the patient remote and pulsegenerator are configured so that the plurality of stimulation levelsselectable by the patient using the patient remote define a monovariantrange of stimulation levels extending from a least selectablestimulation level to a greatest selectable stimulation level.

Further areas of applicability of the present disclosure will becomeapparent from the detailed description provided hereinafter. It shouldbe understood that the detailed description and specific examples, whileindicating various embodiments, are intended for purposes ofillustration only and are not intended to necessarily limit the scope ofthe disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates a nerve stimulation system, whichincludes a clinician programmer and a patient remote used in positioningand/or programming of both a trial neurostimulation system and apermanently implanted neurostimulation system, in accordance withaspects of the invention.

FIGS. 2A-2C show diagrams of the nerve structures along the spine, thelower back and sacrum region, which may be stimulated in accordance withaspects of the invention.

FIG. 3A shows an example of a fully implanted neurostimulation system inaccordance with aspects of the invention.

FIG. 3B shows an example of a neurostimulation system having a partlyimplanted stimulation lead and an external pulse generator adhered tothe skin of the patient for use in a trial stimulation, in accordancewith aspects of the invention.

FIG. 4 shows an example of a neurostimulation system having animplantable stimulation lead, an implantable pulse generator, and anexternal charging device, in accordance with aspects of the invention.

FIG. 5A-5C show detail views of an implantable pulse generator andassociated components for use in a neurostimulation system, inaccordance with aspects of the invention.

FIG. 6 schematically illustrates a nerve stimulation system utilizing acontrol unit with a stimulation clip, a ground patch, twoelectromyography sensors, and ground patch sets connected during theoperation of placing a trial or permanent neurostimulation system, inaccordance with aspects of the invention.

FIGS. 7-8 show signal characteristics of a neurostimulation program, inaccordance with aspects of the invention.

FIG. 9 is a schematic illustration of a patient remote, in accordancewith aspects of the invention.

FIGS. 9-1 to 9-7 are schematic illustrations of a patient remote showinga progression of stimulation levels, in accordance with aspects of theinvention.

FIGS. 9-8 and 9-9 are schematic illustrations of a patient remote with atherapy-remaining display showing levels of therapy remaining for aneurostimulation system, in accordance with aspects of the invention.

FIG. 9-10 is a schematic illustration of a patient remote with anilluminated fault condition indicator, in accordance with aspects of theinvention.

FIG. 10 is a functional block diagram of components of a patient remote,in accordance with aspects of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to neurostimulation treatment systems andassociated devices, as well as methods of treatment,implantation/placement and configuration of such treatment systems. Inone particular embodiment, the invention relates to sacral nervestimulation treatment systems configured to treat overactive bladder(“OAB”) and relieve symptoms of bladder related dysfunction. Inaddition, the descriptions herein may also be used to treat other formsof urinary dysfunction and to treat fecal dysfunction, therefore,throughout the description it should be understood that what isdescribed for OAB applies equally to other forms of urinary dysfunctionand fecal dysfunction. It will be appreciated however that the presentinvention may also be utilized for the treatment of pain or otherindications, such as movement or affective disorders, as will beappreciated by one of skill in the art.

I. Neurostimulation Indications

Neurostimulation (or neuromodulation as may be used interchangeablyhereunder) treatment systems, such as any of those described herein, canbe used to treat a variety of ailments and associated symptoms, such asacute pain disorders, movement disorders, affective disorders, as wellas bladder related dysfunction. Examples of pain disorders that may betreated by neurostimulation include failed back surgery syndrome, reflexsympathetic dystrophy or complex regional pain syndrome, causalgia,arachnoiditis, and peripheral neuropathy. Movement orders include muscleparalysis, tremor, dystonia and Parkinson's disease. Affective disordersinclude depressions, obsessive-compulsive disorder, cluster headache,Tourette syndrome and certain types of chronic pain. Bladder relateddysfunctions include but are not limited to OAB, urge incontinence,urgency-frequency, and urinary retention. OAB can include urgeincontinence and urgency-frequency alone or in combination. Urgeincontinence is the involuntary loss or urine associated with a sudden,strong desire to void (urgency). Urgency-frequency is the frequent,often uncontrollable urges to urinate (urgency) that often result invoiding in very small amounts (frequency). Urinary retention is theinability to empty the bladder. Neurostimulation treatments can beconfigured to address a particular condition by effectingneurostimulation of targeted nerve tissues relating to the sensoryand/or motor control associated with that condition or associatedsymptom.

In one aspect, the methods and systems described herein are particularlysuited for treatment of urinary and fecal dysfunctions. These conditionshave been historically under-recognized and significantly underserved bythe medical community. OAB is one of the most common urinarydysfunctions. It is a complex condition characterized by the presence ofbothersome urinary symptoms, including urgency, frequency, nocturia andurge incontinence. It is estimated that about 33 million Americanssuffer from OAB. Of the adult population, about 30% of all men and 40%of all women live with OAB symptoms.

OAB symptoms can have a significant negative impact on the psychosocialfunctioning and the quality of life of patients. People with OAB oftenrestrict activities and/or develop coping strategies. Furthermore, OABimposes a significant financial burden on individuals, their families,and healthcare organizations. The prevalence of co-morbid conditions isalso significantly higher for patients with OAB than in the generalpopulation. Co-morbidities may include falls and fractures, urinarytract infections, skin infections, vulvovaginitis, cardiovascular, andcentral nervous system pathologies. Chronic constipation, fecalincontinence, and overlapping chronic constipation occur more frequentlyin patients with OAB.

Conventional treatments of OAB generally include lifestyle modificationsas a first course of action. Lifestyle modifications include eliminatingbladder irritants (such as caffeine) from the diet, managing fluidintake, reducing weight, stopping smoking, and managing bowelregularity. Behavioral modifications include changing voiding habits(such as bladder training and delayed voiding), training pelvic floormuscles to improve strength and control of urethral sphincter,biofeedback and techniques for urge suppression. Medications areconsidered a second-line treatment for OAB. These includeanti-cholinergic medications (oral, transdermal patch, and gel) and oralbeta-3 adrenergic agonists. However, anti-cholinergics are frequentlyassociated with bothersome, systemic side effects including dry mouth,constipation, urinary retention, blurred vision, somnolence, andconfusion. Studies have found that more than 50% of patients stop usinganti-cholinergic medications within 90 days due to a lack of benefit,adverse events, or cost.

When these approaches are unsuccessful, third-line treatment optionssuggested by the American Urological Association include intradetrusor(bladder smooth muscle) injections of Botulinum Toxin (BoNT-A),Percutaneous Tibial Nerve Stimulation (PTNS) and Sacral NerveStimulation (SNM). BoNT-A (Botox®) is administered via a series ofintradetrusor injections under cystoscopic guidance, but repeatinjections of Botox are generally required every 4 to 12 months tomaintain effect and Botox may undesirably result in urinary retention. Anumber or randomized controlled studies have shown some efficacy ofBoNT-A in OAB patients, but long-term safety and effectiveness of BoNT-Afor OAB is largely unknown.

Alternative treatment methods, typically considered when the aboveapproaches prove ineffective, is neurostimulation of nerves relating tothe urinary system. Such neurostimulation methods include PTNS and SNM.PTNS therapy consists of weekly, 30-minute sessions over a period of 12weeks, each session using electrical stimulation that is delivered froma hand-held stimulator to the sacral plexus via the tibial nerve. Forpatients who respond well and continue treatment, ongoing sessions,typically every 3-4 weeks, are needed to maintain symptom reduction.There is potential for declining efficacy if patients fail to adhere tothe treatment schedule. Efficacy of PTNS has been demonstrated in a fewrandomized-controlled studies, however, long-term safety andeffectiveness of PTNS is relatively unknown at this time.

II. Sacral Neuromodulation

SNM is an established therapy that provides a safe, effective,reversible, and long-lasting treatment option for the management of urgeincontinence, urgency-frequency, and non-obstructive urinary retention.SNM therapy involves the use of mild electrical pulses to stimulate thesacral nerves located in the lower back. Electrodes are placed next to asacral nerve, usually at the S3 level, by inserting the electrode leadsinto the corresponding foramen of the sacrum. The electrodes areinserted subcutaneously and are subsequently attached to an implantablepulse generator (IPG). The safety and effectiveness of SNM for thetreatment of OAB, including durability at five years for both urgeincontinence and urgency-frequency patients, is supported by multiplestudies and is well-documented. SNM has also been approved to treatchronic fecal incontinence in patients who have failed or are notcandidates for more conservative treatments.

A. Implantation of Sacral Neuromodulation System

Currently, SNM qualification has a trial phase, and is followed ifsuccessful by a permanent implant. The trial phase is a test stimulationperiod where the patient is allowed to evaluate whether the therapy iseffective. Typically, there are two techniques that are utilized toperform the test stimulation. The first is an office-based proceduretermed the Percutaneous Nerve Evaluation (PNE) and the other is a stagedtrial.

In the PNE, a foramen needle is typically used first to identify theoptimal stimulation location, usually at the S3 level, and to evaluatethe integrity of the sacral nerves. Motor and sensory responses are usedto verify correct needle placement, as described in Table 1 below. Atemporary stimulation lead (a unipolar electrode) is then placed nearthe sacral nerve under local anesthesia. This procedure can be performedin an office setting without fluoroscopy. The temporary lead is thenconnected to an external pulse generator (EPG) taped onto the skin ofthe patient during the trial phase. The stimulation level can beadjusted to provide an optimal comfort level for the particular patient.The patient will monitor his or her voiding for 3 to 7 days to see ifthere is any symptom improvement. The advantage of the PNE is that it isan incision free procedure that can be performed in the physician'soffice using local anesthesia. The disadvantage is that the temporarylead is not securely anchored in place and has the propensity to migrateaway from the nerve with physical activity and thereby cause failure ofthe therapy. If a patient fails this trial test, the physician may stillrecommend the staged trial as described below. If the PNE trial ispositive, the temporary trial lead is removed and a permanentquadri-polar tined lead is implanted along with an IPG under generalanesthesia. Other neuromodulation applications may have any number ofelectrodes and more than one lead as the therapy may require.

A staged trial involves the implantation of the permanent quadri-polartined stimulation lead into the patient from the start. It also requiresthe use of a foramen needle to identify the nerve and optimalstimulation location. The lead is implanted near the S3 sacral nerve andis connected to an EPG via a lead extension. This procedure is performedunder fluoroscopic guidance in an operating room and under local orgeneral anesthesia. The EPG is adjusted to provide an optimal comfortlevel for the patient and the patient monitors his or her voiding for upto two weeks. If the patient obtains meaningful symptom improvement, heor she is considered a suitable candidate for permanent implantation ofthe IPG under general anesthesia, typically in the upper buttock area,as shown in FIGS. 1 and 3A.

TABLE 1 Motor and Sensory Responses of SNM at Different Sacral NerveRoots Response Nerve Innervation Pelvic Floor Foot/calf/leg Sensation S2-Primary somatic “Clamp” * of anal Leg/hip rotation, Contraction of basecontributor of pudendal sphincter plantar flexion of entire of penis,vagina nerve for external foot, contraction of calf sphincter, leg, footS3 - Virtually all pelvic “bellows” ** of Plantar flexion of greatPulling in rectum, autonomic functions and perineum toe, occasionallyother extending forward striated mucle (levetor toes to scrotum or labiaani) S4 - Pelvic autonomic “bellows” ** No lower extremity Pulling inrectum and somatic; No leg pr motor stimulation only foot

In regard to measuring outcomes for SNM treatment of voidingdysfunction, the voiding dysfunction indications (e.g., urgeincontinence, urgency-frequency, and non-obstructive urinary retention)are evaluated by unique primary voiding diary variables. The therapyoutcomes are measured using these same variables. SNM therapy isconsidered successful if a minimum of 50% improvement occurs in any ofprimary voiding diary variables compared with the baseline. For urgeincontinence patients, these voiding diary variables may include: numberof leaking episodes per day, number of heavy leaking episodes per day,and number of pads used per day. For patients with urgency-frequency,primary voiding diary variables may include: number of voids per day,volume voided per void and degree of urgency experienced before eachvoid. For patients with retention, primary voiding diary variables mayinclude: catheterized volume per catheterization and number ofcatheterizations per day.

The mechanism of action of SNM is multifactorial and impacts theneuro-axis at several different levels. In patients with OAB, it isbelieved that pudendal afferents can activate the inhibitory reflexesthat promote bladder storage by inhibiting the afferent limb of anabnormal voiding reflex. This blocks input to the pontine micturitioncenter, thereby restricting involuntary detrusor contractions withoutinterfering with normal voiding patterns. For patients with urinaryretention, SNM is believed to activate the pudendal nerve afferentsoriginating from the pelvic organs into the spinal cord. At the level ofthe spinal cord, pudendal afferents may turn on voiding reflexes bysuppressing exaggerated guarding reflexes, thus relieving symptoms ofpatients with urinary retention so normal voiding can be facilitated. Inpatients with fecal incontinence, it is hypothesized that SNM stimulatespudendal afferent somatic fibers that inhibit colonic propulsiveactivity and activates the internal anal sphincter, which in turnimproves the symptoms of fecal incontinence patients. The presentinvention relates to a system adapted to deliver neurostimulation totargeted nerve tissues in a manner that disrupt, inhibit, or preventneural activity in the targeted nerve tissues so as to providetherapeutic effect in treatment of OAB or bladder related dysfunction.In one aspect, the system is adapted to provide therapeutic effect byneurostimulation without inducing motor control of the musclesassociated with OAB or bladder related dysfunction by the deliveredneurostimulation. In another aspect, the system is adapted to providesuch therapeutic effect by delivery of sub-threshold neurostimulationbelow a threshold that induces paresthesia and/or neuromuscular responseor to allow adjustment of neurostimulation to delivery therapy atsub-threshold levels.

B. Positioning Neurostimulation Leads with EMG

While conventional approaches have shown efficacy in treatment ofbladder related dysfunction, there exists a need to improve positioningof the neurostimulation leads and consistency between the trial andpermanent implantation positions of the lead.

Neurostimulation relies on consistently delivering therapeuticstimulation from a pulse generator, via one or more neurostimulationelectrodes, to particular nerves or targeted regions. Theneurostimulation electrodes are provided on a distal end of animplantable lead that can be advanced through a tunnel formed in patienttissue. Implantable neurostimulation systems provide patients with greatfreedom and mobility, but it may be easier to adjust theneurostimulation electrodes of such systems before they are surgicallyimplanted. It is desirable for the physician to confirm that the patienthas desired motor and/or sensory responses before implanting an IPG. Forat least some treatments (including treatments of at least some forms ofurinary and/or fecal dysfunction), demonstrating appropriate motorresponses may be highly beneficial for accurate and objective leadplacement while the sensory response may not be required or notavailable (e.g., patient is under general anesthesia).

Placement and calibration of the neurostimulation electrodes andimplantable leads sufficiently close to specific nerves can bebeneficial for the efficacy of treatment. Accordingly, aspects andembodiments of the present disclosure are directed to aiding andrefining the accuracy and precision of neurostimulation electrodeplacement. Further, aspects and embodiments of the present disclosureare directed to aiding and refining protocols for setting therapeutictreatment signal parameters for a stimulation program implementedthrough implanted neurostimulation electrodes.

Prior to implantation of the permanent device, patients may undergo aninitial testing phase to estimate potential response to treatment. Asdiscussed above, PNE may be done under local anesthesia, using a testneedle to identify the appropriate sacral nerve(s) according to asubjective sensory response by the patient. Other testing procedures caninvolve a two-stage surgical procedure, where a quadri-polar tined leadis implanted for a testing phase to determine if patients show asufficient reduction in symptom frequency, and if appropriate,proceeding to the permanent surgical implantation of a neuromodulationdevice. For testing phases and permanent implantation, determining thelocation of lead placement can be dependent on subjective qualitativeanalysis by either or both of a patient or a physician.

In exemplary embodiments, determination of whether or not an implantablelead and neurostimulation electrode is located in a desired or correctlocation can be accomplished through use of electromyography (“EMG”),also known as surface electromyography. EMG, is a technique that uses anEMG system or module to evaluate and record electrical activity producedby muscles, producing a record called an electromyogram. EMG detects theelectrical potential generated by muscle cells when those cells areelectrically or neurologically activated. The signals can be analyzed todetect activation level or recruitment order. EMG can be performedthrough the skin surface of a patient, intramuscularly or throughelectrodes disposed within a patient near target muscles, or using acombination of external and internal structures. When a muscle or nerveis stimulated by an electrode, EMG can be used to determine if therelated muscle is activated, (i.e. whether the muscle fully contracts,partially contracts, or does not contract) in response to the stimulus.Accordingly, the degree of activation of a muscle can indicate whetheran implantable lead or neurostimulation electrode is located in thedesired or correct location on a patient. Further, the degree ofactivation of a muscle can indicate whether a neurostimulation electrodeis providing a stimulus of sufficient strength, amplitude, frequency, orduration to affect a treatment regimen on a patient. Thus, use of EMGprovides an objective and quantitative means by which to standardizeplacement of implantable leads and neurostimulation electrodes, reducingthe subjective assessment of patient sensory responses.

In some approaches, positional titration procedures may optionally bebased in part on a paresthesia or pain-based subjective response from apatient. In contrast, EMG triggers a measureable and discrete muscularreaction. As the efficacy of treatment often relies on precise placementof the neurostimulation electrodes at target tissue locations and theconsistent, repeatable delivery of neurostimulation therapy, using anobjective EMG measurement can substantially improve the utility andsuccess of SNM treatment. The measureable muscular reaction can be apartial or a complete muscular contraction, including a response belowthe triggering of an observable motor response, such as those shown inTable 1, depending on the stimulation of the target muscle. In addition,by utilizing a trial system that allows the neurostimulation lead toremain implanted for use in the permanently implanted system, theefficacy and outcome of the permanently implanted system is moreconsistent with the results of the trial period, which moreover leads toimproved patient outcomes.

C. Example Embodiments

FIG. 1 schematically illustrates an exemplary nerve stimulation system,which includes both a trial neurostimulation system 200 and apermanently implanted neurostimulation system 100, in accordance withaspects of the invention. The EPG 80 and IPG 10 are each compatible withand wirelessly communicate with a clinician programmer 60 and a patientremote 70, which are used in positioning and/or programming the trialneurostimulation system 200 and/or permanently implanted system 100after a successful trial. As discussed above, the clinician programmercan include specialized software, specialized hardware, and/or both, toaid in lead placement, programming, re-programming, stimulation control,and/or parameter setting. In addition, each of the IPG and the EPGallows the patient at least some control over stimulation (e.g.,initiating a pre-set program, increasing or decreasing stimulation),and/or to monitor battery status with the patient remote. This approachalso allows for an almost seamless transition between the trial systemand the permanent system.

In one aspect, the clinician programmer 60 is used by a physician toadjust the settings of the EPG and/or IPG while the lead is implantedwithin the patient. The clinician programmer can be a tablet computerused by the clinician to program the IPG, or to control the EPG duringthe trial period. The clinician programmer can also include capabilityto record stimulation-induced electromyograms to facilitate leadplacement and programming. The patient remote 70 can allow the patientto turn the stimulation on or off, or to vary stimulation from the IPGwhile implanted, or from the EPG during the trial phase.

In another aspect, the clinician programmer 60 has a control unit whichcan include a microprocessor and specialized computer-code instructionsfor implementing methods and systems for use by a physician in deployingthe treatment system and setting up treatment parameters. The clinicianprogrammer generally includes a user interface which can be a graphicaluser interface, an EMG module, electrical contacts such as an EMG inputthat can couple to an EMG output stimulation cable, an EMG stimulationsignal generator, and a stimulation power source. The stimulation cablecan further be configured to couple to any or all of an access device(e.g., a foramen needle), a treatment lead of the system, or the like.The EMG input may be configured to be coupled with one or more sensorypatch electrode(s) for attachment to the skin of the patient adjacent amuscle (e.g., a muscle enervated by a target nerve). Other connectors ofthe clinician programmer may be configured for coupling with anelectrical ground or ground patch, an electrical pulse generator (e.g.,an EPG or an IPG), or the like. As noted above, the clinician programmercan include a module with hardware and computer-code to execute EMGanalysis, where the module can be a component of the control unitmicroprocessor, a pre-processing unit coupled to or in-line with thestimulation and/or sensory cables, or the like.

In some aspects, the clinician programmer is configured to operate incombination with an EPG when placing leads in a patient body. Theclinician programmer can be electronically coupled to the EPG duringtest simulation through a specialized cable set. The test simulationcable set can connect the clinician programmer device to the EPG andallow the clinician programmer to configure, modify, or otherwiseprogram the electrodes on the leads connected to the EPG.

The electrical pulses generated by the EPG and IPG are delivered to oneor more targeted nerves via one or more neurostimulation electrodes ator near a distal end of each of one or more leads. The leads can have avariety of shapes, can be a variety of sizes, and can be made from avariety of materials, which size, shape, and materials can be tailoredto the specific treatment application. While in this embodiment, thelead is of a suitable size and length to extend from the IPG and throughone of the foramen of the sacrum to a targeted sacral nerve, in variousother applications, the leads may be, for example, implanted in aperipheral portion of the patient's body, such as in the arms or legs,and can be configured to deliver electrical pulses to the peripheralnerve such as may be used to relieve chronic pain. It is appreciatedthat the leads and/or the stimulation programs may vary according to thenerves being targeted.

FIGS. 2A-2C show diagrams of various nerve structures of a patient,which may be used in neurostimulation treatments, in accordance withaspects of the invention. FIG. 2A shows the different sections of thespinal cord and the corresponding nerves within each section. The spinalcord is a long, thin bundle of nerves and support cells that extend fromthe brainstem along the cervical cord, through the thoracic cord and tothe space between the first and second lumbar vertebra in the lumbarcord. Upon exiting the spinal cord, the nerve fibers split into multiplebranches that innervate various muscles and organs transmitting impulsesof sensation and control between the brain and the organs and muscles.Since certain nerves may include branches that innervate certain organs,such as the bladder, and branches that innervate certain muscles of theleg and foot, stimulation of the nerve at or near the nerve root nearthe spinal cord can stimulate the nerve branch that innervate thetargeted organ, which may also result in muscle responses associatedwith the stimulation of the other nerve branch. Thus, by monitoring forcertain muscle responses, such as those in Table 1, either visually,through the use of EMG as described herein or both, the physician candetermine whether the targeted nerve is being stimulated. Whilestimulation at a certain threshold may trigger the noted muscleresponses, stimulation at a sub-threshold level may still providestimulation to the nerve associated with the targeted organ withoutcausing the corresponding muscle response, and in some embodiments,without causing any paresthesia. This is advantageous as it allows fortreatment of the condition by neurostimulation without otherwise causingpatient discomfort, pain or undesired muscle responses.

FIG. 2B shows the nerves associated with the lower back section, in thelower lumbar cord region where the nerve bundles exit the spinal cordand travel through the sacral foramens of the sacrum. In someembodiments, the neurostimulation lead is advanced through the foramenuntil the neurostimulation electrodes are positioned at the anteriorsacral nerve root, while the anchoring portion of the lead proximal ofthe stimulation electrodes are generally disposed dorsal of the sacralforamen through which the lead passes, so as to anchor the lead inposition. FIG. 2C shows detail views of the nerves of the lumbosacraltrunk and the sacral plexus, in particular, the S1-S5 nerves of thelower sacrum. The S3 sacral nerve is of particular interest fortreatment of bladder related dysfunction, and in particular OAB.

FIG. 3A schematically illustrates an example of a fully implantedneurostimulation system 100 adapted for sacral nerve stimulation.Neurostimulation system 100 includes an IPG implanted in a lower backregion and connected to a neurostimulation lead extending through the S3foramen for stimulation of the S3 sacral nerve. The lead is anchored bya tined anchor portion 30 that maintains a position of a set ofneurostimulation electrodes 40 along the targeted nerve, which in thisexample, is the anterior sacral nerve root S3 which enervates thebladder so as to provide therapy for various bladder relateddysfunctions. While this embodiment is adapted for sacral nervestimulation, it is appreciated that similar systems can be used intreating patients with, for example, chronic, severe, refractoryneuropathic pain originating from peripheral nerves or various urinarydysfunctions or still further other indications. Implantableneurostimulation systems can be used to either stimulate a targetperipheral nerve or the posterior epidural space of the spine.

Properties of the electrical pulses can be controlled via a controllerof the implanted pulse generator. In some embodiments, these propertiescan include, for example, the frequency, strength, pattern, duration, orother aspects of the electrical pulses. These properties can include,for example, a voltage, a current, or the like. This control of theelectrical pulses can include the creation of one or more electricalpulse programs, plans, or patterns, and in some embodiments, this caninclude the selection of one or more pre-existing electrical pulseprograms, plans, or patterns. In the embodiment depicted in FIG. 3A, theimplantable neurostimulation system 100 includes a controller in the IPGhaving one or more pulse programs, plans, or patterns that may bepre-programmed or created as discussed above. In some embodiments, thesesame properties associated with the IPG may be used in an EPG of apartly implanted trial system used before implantation of the permanentneurostimulation system 100.

FIG. 3B shows a schematic illustration of a trial neurostimulationsystem 200 utilizing an EPG patch 81 adhered to the skin of a patient,particularly to the abdomen of a patient, the EPG 80 being encasedwithin the patch. In one aspect, the lead is hardwired to the EPG, whilein another the lead is removably coupled to the EPG through a port oraperture in the top surface of the flexible patch 81. Excess lead can besecured by an additional adherent patch. In one aspect, the EPG patch isdisposable such that the lead can be disconnected and used in apermanently implanted system without removing the distal end of the leadfrom the target location. Alternatively, the entire system can bedisposable and replaced with a permanent lead and IPG. When the lead ofthe trial system is implanted, an EMG obtained via the clinicianprogrammer using one or more sensor patches can be used to ensure thatthe leads are placed at a location proximate to the target nerve ormuscle, as discussed previously.

In some embodiments, the trial neurostimulation system utilizes an EPG80 within an EPG patch 81 that is adhered to the skin of a patient andis coupled to the implanted neurostimulation lead 20 through a leadextension 22, which is coupled with the lead 20 through a connector 21.This extension and connector structure allows the lead to be extended sothat the EPG patch can be placed on the abdomen and allows use of a leadhaving a length suitable for permanent implantation should the trialprove successful. This approach may utilize two percutaneous incisions,the connector provided in the first incision and the lead extensionsextending through the second percutaneous incision, there being a shorttunneling distance (e.g., about 10 cm) there between. This technique mayalso minimize movement of an implanted lead during conversion of thetrial system to a permanently implanted system.

In one aspect, the EPG unit is wirelessly controlled by a patient remoteand/or the clinician programmer in a similar or identical manner as theIPG of a permanently implanted system. The physician or patient mayalter treatment provided by the EPG through use of such portable remotesor programmers and the treatments delivered are recorded on a memory ofthe programmer for use in determining a treatment suitable for use in apermanently implanted system. The clinician programmer can be used inlead placement, programming and/or stimulation control in each of thetrial and permanent nerve stimulation systems. In addition, each nervestimulation system allows the patient to control stimulation or monitorbattery status with the patient remote. This configuration isadvantageous as it allows for an almost seamless transition between thetrial system and the permanent system. From the patient's viewpoint, thesystems will operate in the same manner and be controlled in the samemanner, such that the patient's subjective experience in using the trialsystem more closely matches what would be experienced in using thepermanently implanted system. Thus, this configuration reduces anyuncertainties the patient may have as to how the system will operate andbe controlled such that the patient will be more likely to convert atrial system to a permanent system.

As shown in the detailed view of FIG. 3B, the EPG 80 is encased within aflexible laminated patch 81, which include an aperture or port throughwhich the EPG 80 is connected to the lead extension 22. The patch mayfurther an “on/off” button 83 with a molded tactile detail to allow thepatient to turn the EPG on and/or off through the outside surface of theadherent patch 81. The underside of the patch 81 is covered with askin-compatible adhesive 82 for continuous adhesion to a patient for theduration of the trial period. For example, a breathable strip havingskin-compatible adhesive 82 would allow the EPG 80 to remain attached tothe patient continuously during the trial, which may last over a week,typically two weeks to four weeks, or even longer.

FIG. 4 illustrates an example neurostimulation system 100 that is fullyimplantable and adapted for sacral nerve stimulation treatment. Theimplantable system 100 includes an IPG 10 that is coupled to aneurostimulation lead 20 that includes a group of neurostimulationelectrodes 40 at a distal end of the lead. The lead includes a leadanchor portion 30 with a series of tines extending radially outward soas to anchor the lead and maintain a position of the neurostimulationlead 20 after implantation. The lead 20 may further include one or moreradiopaque markers 25 to assist in locating and positioning the leadusing visualization techniques such as fluoroscopy. In some embodiments,the IPG provides monopolar or bipolar electrical pulses that aredelivered to the targeted nerves through one or more neurostimulationelectrodes, typically four electrodes. In sacral nerve stimulation, thelead is typically implanted through the S3 foramen as described herein.

In one aspect, the IPG is rechargeable wirelessly through conductivecoupling by use of a charging device 50 (CD), which is a portable devicepowered by a rechargeable battery to allow patient mobility whilecharging. The CD is used for transcutaneous charging of the IPG throughRF induction. The CD can either be either patched to the patient's skinusing an adhesive or can be held in place using a belt 53 or by anadhesive patch 52, such as shown in the schematic of FIG. 6. The CD maybe charged by plugging the CD directly into an outlet or by placing theCD in a charging dock or station 51 that connects to an AC wall outletor other power source.

The system may further include a patient remote 70 and clinicianprogrammer 60, each configured to wirelessly communicate with theimplanted IPG, or with the EPG during a trial, as shown in the schematicof the nerve stimulation system in FIG. 6. The clinician programmer 60may be a tablet computer used by the clinician to program the IPG andthe EPG. The device also has the capability to recordstimulation-induced electromyograms (EMGs) to facilitate lead placement,programming, and/or re-programming. The patient remote may be abattery-operated, portable device that utilizes radio-frequency (RF)signals to communicate with the EPG and IPG and allows the patient toadjust the stimulation levels, check the status of the IPG batterylevel, and/or to turn the stimulation on or off

FIG. 5A-5C show detail views of the IPG and its internal components. Insome embodiments, the pulse generator can generate one or morenon-ablative electrical pulses that are delivered to a nerve to controlpain or cause some other desired effect, for example to inhibit,prevent, or disrupt neural activity for the treatment of OAB or bladderrelated dysfunction. In some applications, the pulses having a pulseamplitude in a range between 0 mA to 1,000 mA, 0 mA to 100 mA, 0 mA to50 mA, 0 mA to 25 mA, and/or any other or intermediate range ofamplitudes may be used. One or more of the pulse generators can includea processor and/or memory adapted to provide instructions to and receiveinformation from the other components of the implantableneurostimulation system. The processor can include a microprocessor,such as a commercially available microprocessor from Intel® or AdvancedMicro Devices, Inc.®, or the like. An IPG may include an energy storagefeature, such as one or more capacitors, and typically includes awireless charging unit.

One or more properties of the electrical pulses can be controlled via acontroller of the IPG or EPG. In some embodiments, these properties caninclude, for example, the frequency, strength, pattern, duration, orother aspects of the timing and magnitude of the electrical pulses.These properties can further include, for example, a voltage, a current,or the like. This control of the electrical pulses can include thecreation of one or more electrical pulse programs, plans, or patterns,and in some embodiments, this can include the selection of one or morepre-existing electrical pulse programs, plans, or patterns. In oneaspect, the IPG 10 includes a controller having one or more pulseprograms, plans, or patterns that may be created and/or pre-programmed.In some embodiments, the IPG can be programmed to vary stimulationparameters including pulse amplitude in a range from 0 mA to 10 mA,pulse width in a range from 50 μs to 500 μs, pulse frequency in a rangefrom 5 Hz to 250 Hz, stimulation modes (e.g., continuous or cycling),and electrode configuration (e.g., anode, cathode, or off), to achievethe optimal therapeutic outcome specific to the patient. In particular,this allows for an optimal setting to be determined for each patienteven though each parameter may vary from person to person.

As shown in FIGS. 5A-5B, the IPG may include a header portion 11 at oneend and a ceramic portion 14 at the opposite end. The header portion 11houses a feed through assembly 12 and connector stack 13, while theceramic case portion 14 houses an antenna assembly 16 to facilitatewireless communication with the clinician program, the patient remote,and/or a charging coil to facilitate wireless charging with the CD. Theremainder of the IPG is covered with a titanium case portion 17, whichencases the printed circuit board, memory and controller components thatfacilitate the electrical pulse programs described above. In the exampleshown in FIG. 5C, the header portion of the IPG includes a four-pinfeed-through assembly 12 that couples with the connector stack 13 inwhich the proximal end of the lead is coupled. The four pins correspondto the four electrodes of the neurostimulation lead. In someembodiments, a Balseal® connector block is electrically connected tofour platinum/iridium alloy feed-through pins which are brazed to analumina ceramic insulator plate along with a titanium alloy flange. Thisfeed-through assembly is laser seam welded to a titanium-ceramic brazedcase to form a complete hermetic housing for the electronics. The numberof header electrical contacts is a function of the number of electrodesand leads used for any particular system configuration.

In some embodiment, such as that shown in FIG. 5A, the ceramic andtitanium brazed case is utilized on one end of the IPG where the ferritecoil and PCB antenna assemblies are positioned. A reliable hermetic sealis provided via a ceramic-to-metal brazing technique. The zirconiaceramic may comprise a 3Y-TZP (3 mol percent Yttria-stabilizedtetragonal Zirconia Polycrystals) ceramic, which has a high flexuralstrength and impact resistance and has been commercially utilized in anumber of implantable medical technologies. It will be appreciated,however, that other ceramics or other suitable materials may be used forconstruction of the IPG.

In one aspect, utilization of ceramic material provides an efficient,radio-frequency-transparent window for wireless communication with theexternal patient remote and clinician's programmer as the communicationantenna is housed inside the hermetic ceramic case. This ceramic windowhas further facilitated miniaturization of the implant while maintainingan efficient, radio-frequency-transparent window for long term andreliable wireless communication between the IPG and externalcontrollers, such as the patient remote and clinician programmer. TheIPG's wireless communication is generally stable over the lifetime ofthe device, unlike prior art products where the communication antenna isplaced in the header outside the hermetic case. The communicationreliability of such prior art devices tends to degrade due to the changein dielectric constant of the header material in the human body overtime.

In another aspect, the ferrite core is part of the charging coilassembly 15, shown in FIG. 5B, which is positioned inside the ceramiccase 14. The ferrite core concentrates the magnetic field flux throughthe ceramic case as opposed to the metallic case portion 17. Thisconfiguration maximizes coupling efficiency, which reduces the requiredmagnetic field and in turn reduces device heating during charging. Inparticular, because the magnetic field flux is oriented in a directionperpendicular to the smallest metallic cross section area, heatingduring charging is minimized. This configuration also allows the IPG tobe effectively charged at depth of 3 cm with the CD, when positioned ona skin surface of the patient near the IPG and reduces re-charging time.

FIG. 6 shows a setup for a test stimulation and EMG sensing using aclinician programmer 60. As discussed above, the clinician programmer 60is a tablet computer with software that runs on a standard operatingsystem. The clinician programmer 60 includes a communication module, astimulation module and an EMG sensing module. The communication modulecommunicates with the IPG and/or EPG in the medical implantcommunication service frequency band for programming the IPG and/or EPG.

In order to confirm correct lead placement, it is desirable for thephysician to confirm that the patient has both adequate motor andsensory responses before transitioning the patient into the staged trialphase or implanting the permanent IPG. However, sensory response is asubjective evaluation and may not always be available, such as when thepatient is under general anesthesia. Experiments have shown thatdemonstrating appropriate motor responses is advantageous for accurateplacement, even if sensory responses are available. As discussed above,EMG is a tool which records electrical activity of skeletal muscles.This sensing feature provides an objective criterion for the clinicianto determine if the sacral nerve stimulation results in adequate motorresponse rather than relying solely on subjective sensory criteria. EMGcan be used not only to verify optimal lead position during leadplacement, but also to provide a standardized and more accurate approachto determine electrode thresholds, which in turn provides quantitativeinformation supporting electrode selection for programming. Using EMG toverify activation of motor responses can further improve the leadplacement performance of less experienced operators and allow suchphysicians to perform lead placement with confidence and greateraccuracy.

In one aspect, the system is configured to have EMG sensing capabilityduring re-programming, which can be particularly valuable. Stimulationlevels during re-programming are typically low to avoid patientdiscomfort which often results in difficult generation of motorresponses. Involuntary muscle movement while the patient is awake mayalso cause noise that is difficult for the physician to differentiate.In contrast to conventional approaches, EMG allows the clinician todetect motor responses at very low stimulation levels (e.g.,sub-threshold), and help them distinguish a motor response originated bysacral nerve stimulation from involuntary muscle movement.

Referring to FIG. 6, several cable sets are connected to the CP. Thestimulation cable set consists of one stimulation mini-clip 3 and oneground patch 5. It is used with a foramen needle 1 to locate the sacralnerve and verify the integrity of the nerve via test stimulation.Another stimulation cable set with four stimulation channels 2 is usedto verify the lead position with a tined stimulation lead 20 during thestaged trial. Both cable sets are sterilizable as they will be in thesterile field. A total of five over-the-shelf sensing electrode patches4 (e.g., two sensing electrode pairs for each sensing spot and onecommon ground patch) are provided for EMG sensing at two differentmuscle groups (e.g., perineal musculature and big toe) simultaneouslyduring the lead placement procedure. This provides the clinician with aconvenient all-in-one setup via the EMG integrated clinician programmer.Typically, only one electrode set (e.g., two sensing electrodes and oneground patch) is needed for detecting an EMG signal on the big toeduring an initial electrode configuration and/or re-programming session.Typically, these over-the-shelf EMG electrodes are also provided sterilethough not all cables are required to be connected to the sterile field.The clinician programmer 60 allows the clinician to read the impedanceof each electrode contact whenever the lead is connected to an EPG, anIPG or a clinician programmer to ensure reliable connection is made andthe lead is intact. In some embodiments, any electrode with unacceptableimpedance can be locked out from being assigned as an anode or cathode.Unacceptable impedance can be impedance less than 50 or greater than3,000 Ohms, or alternatively less than 500 or greater than 5,000 Ohms.The clinician programmer 60 is also able to save and display previous(e.g., up to the last four) programs that were used by a patient to helpfacilitate re-programming. In some embodiments, the clinician programmer60 further includes a USB port for saving reports to a USB drive and acharging port. The clinician programmer may also include physical on/offbuttons to turn the clinician programmer on and off and/or to turnstimulation on and off.

In some embodiments, the IPG, as well as the EPG, may be configured withtwo stimulation modes: continuous mode and cycling mode, such as shownin FIG. 7. The cycling mode saves energy in comparison to the continuousmode, thereby extending the recharge interval of the battery andlifetime of the device. The cycling mode may also help reduce the riskof neural adaptation for some patients. Neural adaptation is a changeover time in the responsiveness of the neural system to a constantstimulus. Thus, cycling mode may also mitigate neural adaptation so toprovide longer-term therapeutic benefit. FIG. 7 shows an example ofstimulation in a cycling mode, in which the duty cycle is thestimulation on time over the stimulation-on time plus thestimulation-off time.

In some embodiments, the IPG/EPG is configured with a ramping feature,such as shown in the example of FIG. 8. In these embodiments, thestimulation signal is ramped up and/or down between the stimulation-onand stimulation-off levels. This feature helps reduce the sudden“jolting” or “shocking” sensation that some patients might experiencewhen the stimulation is initially turned on or at the cycle-on phaseduring the cycling mode. This feature is particularly of benefit forpatients who need relative high stimulation settings and/or for patientswho are sensitive to electrical stimulation.

D. Patient Remote Control

The patient remote (e.g. FIG. 1, element 70) is provided to allow apatient to adjust the stimulation level of the electrical pulsegenerator. The patient remote can be used to wirelessly communicate withand control either an EPG (e.g., during a trial phase) or an IPG (e.g.,for a permanent neurostimulation system). In some implementations,different patient remotes can be provided to control the EPG and theIPG, whereas in other implementations, a single patient remote can beprogrammed or reprogrammed to control either an EPG or an IPG. Aparticular patient remote can be configured to link with and wirelesslycommunicate with only a single EPG or IPG so as to avoid patientsaltering the stimulation of others.

The degree of adjustment permitted to the patient through the patientremote can be limited, such that while the patient can incrementallyincrease or decrease the therapy delivered by the pulse generator, andcan turn stimulation on or off, the level of stimulation therapy by thepulse generator whenever the pulse generator is applying stimulation ismaintained within a clinically effective combination of settings. Byproviding a limited range of adjustment to a patient through the patientremote, the patient is given a straightforward and simple tool forsituational control of the pulse generator and overall neurostimulationsystem, allowing for the use of different stimulation levels (includingno stimulation when appropriate) while the patient is awake, while thepatient is asleep, while the patient is engaged in specific activities,or in other situations. However, the patient may not be presented with aselection of alternative therapies or multivariate operational programsvia the patient remote that may confuse the patient or take the pulsegenerator outside of a clinically effective range. In some aspects, thepatient remote can be configured to provide monovariant control to thepatient. For example, the patient remote can be limited to varying astimulation level of the stimulation program, while the other attributesof the stimulation program (e.g. duration, electrode configuration,pulse width, etc.) are maintained. The clinically effective range of thepulse generator can be determined by a physician or the clinicianprogrammer when setting the parameters of the pulse generator andneurostimulation system.

The patient remote can allow a patient to turn on and turn off the pulsegenerator, where turning off the pulse generator may be desirable forthe patient when performing activities that may inadvertently interferewith, or be inadvertently interfered by, an active pulse generator andthe nerves stimulated by the pulse generator. For example, as noted inTable 1 above, innervation of the S3 sacral nerve can cause a responsein the plantar flexion of the great toe or other toes. Thus, it may bedesirable to provide a patient the option to turn off the pulsegenerator while driving, carrying heavy objects, or performing otheractivities that can strain the foot or toes and may therebyinadvertently trigger a pulling sensation in the rectum. Moreover, itmay be desirable to provide a patient the option to automaticallyrestore the pulse generator to a previous level of stimulation when thepulse generator is turned on after a period of being turned off. In manycases, the previous level of stimulation can be the last storedstimulation level of the patient remote. In further implementations, thepatient remote can provide the patient with an indication of batterystatus and/or therapy remaining for the neurostimulation system andpulse generator.

Structurally, the patient remote can include a portable housing, withone or more switches and one or more displays on or embedded within theexterior surface of the portable housing. The patient remote can have anactivation switch and a stimulation-increase switch disposed on anexterior surface of the patient remote, allowing the patient (or otheroperator) to activate the patient remote and then to instruct theneurostimulation system to increase the stimulation level of the pulsegenerator. The patent remote can also include any combination of astimulation-decrease switch (allowing the patient to decrease thestimulation level), a stimulation-level display, a therapy-remainingdisplay, and/or a fault condition display disposed on the exteriorsurface of the patient remote.

In other words, the portable housing of the patient remote can be sizedor dimensioned so as to fit within a single hand of a patient. Thepatient remote can accordingly be operable within a single hand of apatient, or another operator. Further, in the context of the presentdisclosure, the switches of the patient remote can instead be buttons,formed as part of the body of the patient remote, or formed to passthrough shaped holes in the surface of the patient remote. Inimplementations of the patient remote having buttons, the buttons can bespring biased or otherwise supported so as to provide a degree ofresistance to actuation and/or to restore a button to a default statusafter actuation is completed and the button is released. Any givenswitch or button on the patient remote can be located within adepression of the external surface of the patient remote, on a flatsurface of the external surface of the patient remote, or on a convexsurface of the external surface of the patient remote. Moreover, anygiven switch or button on the patient remote can have a profile that isflush with the external surface of the patient remote, elevated from theexternal surface of the patient remote, or inset/depressed within theexternal surface of the patient remote.

While the terms “switches” and “buttons” are used in the describedembodiments to illustrate various concepts, it is appreciated that suchterms can encompass any actuation feature that is operable by a user toeffect a change in state associated with the patient remote. A change instate can include a change in an activation state of the patient remote,or a mode of the pulse generator and a stimulation level of the IPG orEPG that is controlled by the patient remote. For example, the actuationfeature can be a button, lever, knob, or an optical or touch sensor orany suitable feature that allows a user to effect the change in state byinteraction with the feature. In some embodiments, the actuationfeatures can include portions of a touch screen displayed to a user.

FIG. 9 is a schematic illustration of a patient remote 900 showing thestructure of a portable housing 902. The portable housing 902 has anexterior surface, and in many embodiments the patient remote 900 canhave a control surface 903 on a top side of the exterior surface whereoperational switches and display elements can be disposed. In variousaspects, the control surface 903 can be constructed of a material thatis the same or different as the rest of the portable housing 902. Inother embodiments, the portable housing 902 can have operationalswitches or display elements on a bottom side or lateral sides of theportable housing 902. The portable housing 902 can be constructed fromplastics, lightweight metals (e.g., aluminum), or a combination thereof,and can be designed and constructed to be of a size such that thepatient remote 900 can be held and operated in a single hand of apatient. The patient remote 900 can have an oblong, elongated,rectangular, spherical, square, ellipsoid, or irregular shape, or acombination thereof. The patient remote 900 can be constructed to bewaterproof, where any structural seams of the portable housing 902 canhave an airtight interface or sealed with an additional polymer orchemical compound. The portable housing 902 can further be designed toattach as a fob device, configured to be carried daily, having amechanical coupling structure 916 to attach the patient remote 900 witha key ring, karabiner, or other such mounting element.

The patient remote 900 can include within the interior of the portablehousing 902 transmission circuitry configured to interface with thepulse generator, a battery that functions as a power source for thepatient remote, and control electronics. Control electronics in theinterior of the portable housing 902 can be operatively coupled to relaysignals to the transmission circuitry for controlling control the pulsegenerator corresponding to actuation of the one or more switchesdisposed on the exterior surface of the portable housing 902. Inalternative aspects, the patient remote 900 can include circuitry tocommunicate with the clinician programmer (CP).

The transmission circuitry can include a radio frequency (RF)transmitter that communicates with other system elements on the MedicalImplant Communication Service (MICS) frequency band (MedRadio 402-405MHz). The wireless communication between the patient remote 900 and thepulse generator to which the patient remote 900 sends instructions canhave an operational range of up to three feet, in addition totransmission through the tissue of a patient, in embodiments where thepulse generator is an IPG implanted in the patient. A patient remote 900having any or all of an activation switch 904, stimulation-increaseswitch 906, or stimulation-decrease switch 908 (where any or all ofactivation switch 904, stimulation-increase switch 906, orstimulation-decrease switch 908 can be buttons) disposed on the exteriorsurface of the portable housing 902 can be configured such thatactuation of such switches and/or buttons (where actuation can bedepressing, triggering, toggling, or otherwise operating the switch orbutton) causes the control electronics and/or transmission circuitry ofthe patient remote 900 to relay a signal to a neurostimulation systemand/or to execute a function of the patient remote 900 itself. In someaspects, the battery that powers the patient remote 900 can be apermanent battery having an operational life of three or more years. Inalternative aspects, the battery that powers the patient remote 900 canbe a replaceable or a rechargeable battery.

In some embodiments, the activation switch 904 (alternatively referredto as a “link switch”) can be disposed on the control surface 903, andin particular embodiments the activation switch 904 can be disposed in arecessed region of the control surface 903. In embodiments where theactivation switch 904 is disposed in a recess of the control surface903, activation switch 904 is designed to be actuation due to deliberateeffort. In other words, where the structure of the activation switch 904is disposed within the recess, accidental or inadvertent actuation ofthe activation switch 904 due to incidental physical contact with theexterior surface of the portable housing 902 or contact with othersections of the control surface 903 can be avoided by providingsufficient physical resistance to a throw of the switch. Moresuccinctly, in various embodiments, the activation switch 904 isrecessed so as to avoid accidental depression by the user when thepatient remote 900 is stored in a pocket or purse of the patient. Inthese embodiments, the recess can have a sufficient depth relative tothe size of the activation switch 904 such that the height of theactivation switch 904 is shorter than the depth of the recess, and thusthe activation switch 904 does not extend out of the recess.

The activation switch 904 operates to switch the patient remote 900between an asleep mode and an awake mode. When the patient remote 900 isin an asleep mode, actuation of the activation switch 904 causes thepatient remote to switch to the awake mode and to interrogate theneurostimulator to wirelessly retrieve data regarding the status of theneurostimulation system and/or pulse generator. The data retrieved fromthe neurostimulation system can include the current stimulation level ofthe pulse generator, which can be stored in a processor and/or memory ofthe pulse generator. When the patient remote 900 is in the awake mode,actuation of the activation switch 904 causes the patient remote 900 toswitch to the asleep mode. When the patient remote 900 is in the asleepmode, the stimulation-increase switch 906 and the stimulation-decreaseswitch 908 (both also disposed on the control surface 903) areinactivated, such that actuation of either the stimulation-increaseswitch 906 or the stimulation-decrease switch 908 does not cause thepatient remote 900 to send any signal with transmission circuitry withinthe portable housing 902. When the patient remote 900 is in the awakemode, the stimulation-increase switch 906 and the stimulation-decreaseswitch 908 are active, such that actuation of either thestimulation-increase switch 906 or the stimulation-decrease switch 908causes the patient remote 900 to send a corresponding instruction signalwith transmission circuitry within the portable housing 902. When in theawake mode, if the patient remote 900 is inactive for a set period oftime (e.g. none of the activation switch 904, stimulation-increaseswitch 906, or stimulation-decrease switch 908 are actuated for the setperiod of time), the patient remote can automatically switch to theasleep mode. In some aspects, the set period of time after which thepatient remote 900 will automatically switch to the asleep mode can befive (5) to sixty (60) seconds, or any increment or gradient of timewithin that range. In specific aspects, the set period of time afterwhich the patient remote 900 will automatically switch to the asleepmode can be ten (10) seconds.

The control surface 903 can include a stimulation-increase switch 906coupled to control electronics and transmission circuitry disposedwithin the portable housing 902. Actuation of the stimulation-increaseswitch 906 can relay an instruction signal to the pulse generator (i.e.,through the control electronics and transmission circuitry of thepatient remote 900), where the instruction signal can be selected basedon duration of time that the stimulation-increase switch 906 isactuated. When the stimulation-increase switch 906 is actuated for afirst period of time, the patient remote 902 can send an instructionsignal to the pulse generator to incrementally increase the stimulationlevel of the pulse generator. The first period of time will generally bea period of time that is shorter than a threshold. The threshold maygenerally be between 0.25 and 5 seconds, with the time period for alonger switch actuation threshold time being sufficient to assure thatthe longer duration switch actuation is clearly intentional, typicallybeing three seconds or more. Increasing the stimulation level of thepulse generator can be limited to a maximum selectable level of therapy.When the stimulation-increase switch 906 is actuated for a second,longer period of time, the patient remote 902 can send an instructionsignal to the pulse generator to restore the stimulation level of thepulse generator to a previously stored stimulation level. The secondperiod of time can be three seconds or more. In some aspects, when thepulse generator is instructed to restore the previously storedstimulation level, the pulse generator can gradually ramp up (as shownin FIG. 8) to help reduce any sudden “jolting” or “shocking” sensationthat some patients might experience when the stimulation is turned on.

In situations where a patient has turned off the pulse generator,providing a method to automatically return the stimulation of the pulsegenerator to a previously stored stimulation level allows a patient toefficiently and automatically restore the neurostimulation system to adesired function or status, avoiding the need for repetitive adjustmentof the stimulation level. In many embodiments, the previously storedstimulation level can be the last stimulation level the pulse generatorwas set to before turning off the neurostimulation system. In someaspects, the data indicating the last stimulation level can be stored ina memory of the pulse generator which is retrieved by the patent remote900 when the patient remote 900 switches from the asleep mode to theawake mode. In other aspects, the stimulation level can be stored in amemory of the circuitry within the patient remote 900 portable housing902.

The stimulation-increase switch 906 can further have a visible and/ortactile surface or feature shaped to indicate to an operator that thestimulation-increase switch 906 is configured to increase or restore thestimulation level of the pulse generator (e.g., as an upward arrow, as aplus sign, etc.). In some aspects, the stimulation-increase switch 906can be relatively larger than any stimulation-decrease switch 908 alsodisposed on the exterior of the portable housing 902.

The control surface 903 can also include a stimulation-decrease switch908 coupled to control electronics and transmission circuitry disposedwithin the portable housing 902. Actuation of the stimulation-decreaseswitch 908 can relay an instruction signal to the pulse generator, wherethe instruction signal can be selected based on duration of time thatthe stimulation-decrease switch 908 is actuated. When thestimulation-decrease switch 908 is actuated for the first period oftime, the patient remote 902 can send a signal to the pulse generatorincrementally decrease the stimulation level of the pulse generator,with the time period for a longer switch actuation threshold time beingsufficient to assure that the longer duration switch actuation isclearly intentional, typically being three seconds or more. If thestimulation level of the pulse generator is at the minimum selectablelevel of therapy, actuation of the stimulation-decrease switch 908 forthe first period of time can turn off stimulation by the pulsegenerator. When the stimulation-decrease switch 908 is actuated for asecond period of time, the patient remote 902 can send a signal to thepulse generator to store the status of the current stimulation level ina memory and turn off stimulation by the pulse generator. The secondperiod of time can be three seconds or more. In some aspects, when thepulse generator is instructed to turn off stimulation, the pulsegenerator can gradually ramp down (as shown in FIG. 8) to a zerostimulation status.

The stimulation-decrease switch 908 can further have a visible and/ortactile surface or feature shaped to indicate to an operator that thestimulation-decrease switch 908 is configured to decrease thestimulation level of the pulse generator or turn off stimulation by thepulse generator (e.g., as a downward arrow, as a minus sign, etc.). Insome aspects, the memory in which the stimulation level is stored in thepatient remote, or alternately the memory may be stored in the pulsegenerator. In alternative aspects, the stimulation-increase switch 906and the stimulation-decrease switch 908 can be relatively equal in size.

The incremental increase or decrease of pulse generator stimulationlevel by the patient remote 900 can be proportional to an existing orcurrent stimulation level. In many aspects, the incremental increase ordecrease of pulse generator stimulation level can be a change of apredetermined degree. The predetermined degree can be a percentage of astimulation level, a fraction of a stimulation level, a specific orstatic increment of stimulation level, a proportional increment ofstimulation level, a range-dependent increment of stimulation level, avariable increment of stimulation level, or the like. In someembodiments, each incremental change can be five percent (5%), more thanfive percent (5%), or ten percent (10%) of the existing stimulationlevel, a maximum stimulation level, or a baseline stimulation level. Forexample, if a pulse generator is delivering treatment at a stimulationlevel of 2.0 mA, a single step up increasing the stimulation level canbe 0.2 mA (10% of 2.0 mA), thereby increasing stimulation to 2.2 mA. Asubsequent step up increasing the stimulation level can be 0.22 mA (10%of 2.2 mA), thereby increasing stimulation to 2.42 mA. Similarly, if apulse generator is delivering treatment at a stimulation level of 4.0mA, a single step down decreasing the stimulation level can be 0.4 mA(10% of 4.0 mA), thereby decreasing stimulation to 3.6 mA. In variousembodiments, the step size by which the pulse generator stimulationlevel is changed can be 1% to 25% of the existing stimulation level, orany increment or gradient of a percentage within that range. The numberof available treatment levels may be between 3 and 15, typically beingbetween 4 and 10, and often being between 5 and 8.

In some alternative embodiments, for example, if a pulse generator isdelivering treatment at a baseline or nominal stimulation level of 3.0mA, a single step up increasing the stimulation level can be ten percentof the baseline stimulation, 0.3 mA (10% of 3.0 mA), thereby increasingstimulation to 3.3 mA. A subsequent step up increasing the stimulationlevel can also be based on the baseline stimulation level, that stepagain being 0.3 mA, thereby increasing stimulation to 3.6 mA. Furtherwithin this exemplary embodiment, a single step down decreasingstimulation from a baseline level of 3.0 mA can lower the currentstimulation level to 2.7 mA, and a subsequent step down can decrease thecurrent stimulation level to 2.4 mA.

In further alternative embodiments, each step of stimulation level canbe based on a percentage of a maximum stimulation level. For example, ifa pulse generator has a maximum treatment stimulation level of 4.0 mA,each step of stimulation level change can be ten percent of the maximumstimulation level, 0.4 mA (10% of 4.0 mA). Thus, relative to the maximumstimulation level, a single step down decreasing the stimulation levelcan be at 3.6 mA, a subsequent step down decreasing the stimulationlevel can be at 3.2 mA, and so forth.

In other alternative embodiments, the patient remote 900 can operatehaving an automated proportional stimulation step level increments. Forexample, when the available stimulation range is within a loweramplitude range, the incremental steps can be smaller than thoseassociated with a higher amplitude range. For example, under conditionswhere the amplitude range of stimulation level for the patient remote900 is less than 1.0 milliamp (<1.0 mA), the default increment for astep of simulation level can be 0.05 mA. However, under conditions wherethe amplitude range of stimulation level for the patient remote 900 isfrom 1.0 to 3.0 milliamps (1.0-3.0 mA), the default increment for a stepof simulation level can be 0.10 mA. Further, under conditions where theamplitude range of stimulation level for the patient remote 900 isgreater than 3.0 milliamps (>3.0 mA), the default increment for a stepof simulation level can be 0.20 mA. The proportional change instimulation level step can be varied depending on the amount oftreatment required, the number of amplitude ranges, the breadth ofamplitude ranges, and/or according to other factors controlling theoperation of the patient remote 900. The above described incrementalsteps can also be applied when determining electrode thresholds duringelectrode characterization and/or programming.

In some embodiments, the patient remote 900 can be set to incrementallyadjust stimulation by a step-size defined by a relationship between amaximum stimulation level (I_(max)) and a baseline, also referred to asa nominal or normal stimulation level (I_(n)). For example, the I_(max)and the I_(n) can be determined and set-up by a physician programmingthe patient remote 900 via the clinician programmer. The amplitude ofI_(max) can be set according to the comfort level of a patient (e.g.stimulation level just below where any pain or discomfort is reported bythe patient). Where a difference between I_(max) and I_(n) is ΔI, theincrement step size can be a set proportion or percentage of ΔI, forexample steps sizes of ½ ΔI, ⅓ΔI, or ¼ AI. In some embodiments, the CPautomatically sets such an incremental step size (e.g. ⅓ΔI) with the IPGor EPG, for example during electrode characterization and/orprogramming. Likewise, patient remote 900 can be programmed with astep-size that corresponds to the step-size used by the CP inprogramming the IPG or EPG. The amount by which the stimulation levelscan be adjusted below the nominal stimulation level (e.g. lower range)can be defined to mirror the incremental range between I_(max) and I_(n)(e.g. upper range). For example, where the increment step size isdefined as ⅓ΔI, the range over which the stimulation level can beincrementally adjusted by the patient remote includes seven stimulationlevels, where the nominal or normal stimulation level I_(n) is in themiddle of those seven stimulation levels, incrementing up or down at ⅓ΔIper step allows for a range of stimulation levels that reaches themaximum stimulation level I_(max) on one end of the available treatmentrange, and a minimum stimulation level that mirrors I_(max) on the otherend of the available treatment range, as shown below:

−ΔI −⅔ΔI −⅓ΔI I_(n) +⅓ΔI +⅔ΔI +ΔI (where +ΔI above I_(n) is I_(max and)−ΔI is I_(min)).

By programming the patient remote 900 to increment stimulation of acoupled pulse generator by a predetermined degree such as ⅓ΔI, a fullrange of stimulation levels can be achieved relative to a relationshipbetween I_(max) that matches the comfort level of a patient and thenominal stimulation level corresponding to optimized clinicallyeffective therapy. It is understood that the selection of a stimulationlevel increment step size by programming the patient remote can allowfor setting of a stimulation level increment step to be a specificpercentage of a maximum stimulation level, or proportional to a rangebetween the maximum stimulation level and the nominal stimulation level.In some embodiments, the pulse generator is configured to adjuststimulation incrementally according to a step-size, such as described inany of the embodiments described herein, in response to an increase ordecrease command received from the patient remote. In one aspect, thecommand can include the step-size by which the stimulation level isadjusted or the command can invoke an incremental adjustment based on astep-size increment stored on a memory of the pulse generator.

In various embodiments, the patient remote 900 can increase and/ordecrease the stimulation level by a predetermined percentage. In someembodiments, the predetermined percentage is a set percentage within arange between 5% and 20%, such as about 10% (+/−2%). In someembodiments, the predetermined percentage is the same for incrementalincreases and decreases, while in other embodiments, the increaseincrement differs from that of the decrease increment.

The control surface 903 can include a stimulation-level display 910embedded in the portable housing 902, and electronically coupled tocontrol electronics and transmission circuitry disposed within theportable housing 902 such that the stimulation-level display 910 canindicate the stimulation level being delivered by the pulse generator toa patient. In some embodiments, the stimulation-level display 910 caninclude a plurality of lights or light emitting diodes (LEDs) arrangedon the control surface, where an illuminated subset of the total numberof the plurality of lights or LEDs can indicate the current stimulationlevel of the pulse generator. In some aspects, the stimulation-leveldisplay 910 can include seven (7) white-light LEDs. Thestimulation-level display 910 can have the plurality of LEDs arranged ina pattern to reflect increases and decreases to the stimulation level ofthe pulse generator. In arrangements of the stimulation-level display910 with seven LEDs as illustrated in FIG. 9, a first LED 910-1 canindicate that the pulse generator is set to deliver a stimulation levelat the minimum power selectable via the patient remote 900. In sucharrangements of the stimulation-level display 910 with seven LEDs, asecond LED 910-2, a third LED 910-3, a fourth LED 910-4, a fifth LED910-5, and a sixth LED 910-6, can indicate (as read from left to right,optionally with all of the lower-level LEDs remaining illuminated asstimulation level increases) progressively increasing power ofstimulation levels selectable via the patient remote 900 that the pulsegenerator is set to deliver. Also in such arrangements, illumination ofa seventh LED 910-7 can indicate (optionally with all otherstimulation-level LEDs also being illuminated) that the pulse generatoris set to deliver a stimulation level at the maximum power selectablevia the patient remote 900. In other aspects the stimulation-leveldisplay 910 can include green-light, amber-light, or other colored-lightLEDs, which can also provide a relative qualitative indication of thepower of each stimulation level of the pulse generator. The LEDs usedfor the stimulation-level display 910 can be of at least three (3) orfour (4) varying sizes to provide a relative qualitative indication ofthe power of each stimulation level of the pulse generator. In otherwords, relatively smaller LEDs can be used for the stimulation levelscloser or trending toward the minimum power selectable via the patientremote 900 and relatively larger LEDs can be used for the stimulationlevels closer or trending toward the maximum power selectable via thepatient remote 900.

As noted above, a patient remote 900 can be configured to be used withany appropriate respective pulse generator, such that the patient remote900 can link with and wirelessly communicate with only a single EPG orIPG, so as to avoid inadvertent and unintentional activation,alteration, or triggering of stimulation of other pulse generators.Accordingly, in implementations of the system, a specific patient remote900 can be paired with a specific pulse generator (e.g., an IPG, an EPG,or the like) such that the patient remote 900 will only, or at leastprimarily, operate to interact with the paired pulse generator. Thepairing of a patient remote 900 and a specific pulse generator can beestablished by setting the patient remote 900 and the specific pulsegenerator to transmit and receive data at the same predeterminedwireless or radio frequency. While the clinician programmer can be usedto set up or configure a patient remote 900, or establish the paringbetween a patient remote 900 and a pulse generator, in operation formanaging stimulation levels, the patient remote 900 only and/or directlycommunicates with the pulse generator.

FIGS. 9-1 to 9-7 are schematic illustrations of a patient remote showingan increasing progression of stimulation levels by the stimulation-leveldisplay 910 LEDs. As noted above, when a patient remote 900 is turned onby actuation of the activation switch 904, the patient remote canwirelessly interrogate and retrieve the current stimulation level of apulse generator from the neurostimulation system. The patient remote 900can indicate to a patient that the patient remote 900 is transitioningfrom the asleep mode to the awake mode by cycling illumination of thestimulation-level display 910 LEDs. Once the current stimulation levelof the pulse generator is retrieved by the patient remote, thestimulation-level display 910 can illuminate a corresponding number ofLEDs to indicate to a patient the current stimulation level of the pulsegenerator. At any given stimulation level, the LED indicating thatstimulation level can be illuminated along with all of the LEDsrepresentative of lower stimulation levels. In other aspects, at anygiven stimulation level, the patient remote 900 can illuminate only theLED indicating that specific stimulation level.

The available stimulation levels of the pulse generator can beprogrammed relative to a baseline stimulation level, and the patientremote 900 can be configured provide a limited range of selectablestimulation levels either greater than and/or less than the baselinestimulation level, and ideally both. The baseline stimulation level canbe selected to correspond to illuminate any one of a plurality of LEDsfor the stimulation-level display 910, which can further indicate thenumber of selectable stimulation levels greater than and less than thebaseline stimulation level. In some embodiments, the pulse generator canbe programmed to have three selectable stimulation levels greater thanthe baseline stimulation level and three selectable stimulation levelsless than the baseline stimulation level. In such embodiments, when thepulse generator is set to the baseline stimulation level, the fourth LED910-4 on the patient remote 900 is illuminated (optionally along withfirst, second, and third LEDs). In other embodiments, the pulsegenerator can be programmed to have four selectable stimulation levelsgreater than the baseline stimulation level and two selectablestimulation levels less than the baseline stimulation level. In suchembodiments, when the pulse generator is set to the baseline stimulationlevel, the third LED 910-3 of the patient remote 900 is illuminated(optionally along with first and second LEDs). In alternative aspects,the pulse generator can be programmed such that at the baselinestimulation level, one of the second LED 910-2, the fifth LED 910-5, orthe sixth LED 910-6 on the patient remote 900 is illuminated, withcorresponding selectable stimulation levels greater than and less thanthe baseline stimulation level.

Moreover, the baseline stimulation level can be selected to ensure thatany adjustment to the therapy via the patient remote remains within aclinically effective range whenever stimulation is applied. In someaspects the clinically effective range of stimulation by the pulsegenerator can be from about 0.5 mA to about 4 mA. In other aspects, theclinically effective range of stimulation by the pulse generator can befrom about 1 mA to about 3 mA. In alternative aspects, the idealclinically effective range of stimulation by the pulse generator can befrom about 0.3 mA to about 2.5 mA, while further for such aspects,stimulation by the pulse generator that is less than 0.3 mA and betweenfrom about 2.5 mA to about 4 mA can also be clinically effective atproviding treatment. In some embodiments, stimulation is limited tobelow 4 mA. It is appreciated that the above ranges can be utilized incharacterizing and/or programming the neurostimulation device as well.For example, electrodes with stimulation thresholds that provide adesired parameter (e.g. sensory or motor response) an can be categorizedas to their suitability for delivering neurostimulation based on whichrange the threshold lies. For example, in some embodiments, electrodeswith a threshold between 0.3-2.5 mA can be considered preferredelectrodes for use in neurostimulation therapy delivery, electrodes withthresholds less than 0.3 mA and between 2.5-4 mA can be consideredacceptable, and electrodes with thresholds greater than 4 mA can beconsidered unacceptable for delivering neurostimulation. It isunderstood that these ranges are an example that is applicable tocertain embodiments and certain therapies (e.g. sacral neuromodulationfor treatment of OAB and fecal incontinence) and that various otherranges can apply to various other neurostimulation systems and/ortherapies.

Accordingly, the baseline stimulation level can be selected to have (1)a pulse amplitude or power within the clinically effective range and (2)a proportional incremental change for increasing or decreasingstimulation relative to the baseline stimulation level such that, ateither the maximum or minimum stimulation level selectable via thepatient remote, the therapy delivered by the pulse generator remainswithin the clinically effective range. In further embodiments, theclinically effective range of the pulse generator can include pulseshaving a pulse amplitude in a range between 0 mA to 1,000 mA, 0 mA to100 mA, 0 mA to 50 mA, or 0 mA to 25 mA.

In an exemplary embodiment, the pulse generator can be programmed tohave a baseline stimulation of 2.0 mA with three selectable stimulationlevels greater than the baseline stimulation level and three selectablestimulation levels less than the baseline stimulation level, where eachstep of adjustment can be ten percent (10%) of the existing or currentstimulation level. In such an embodiment, the baseline stimulation levelof 2.0 mA is represented in the stimulation-level display 910 by thefourth LED 910-4 being illuminated, the minimum stimulation levelselectable by the patient remote 900 is 1.458 mA (represented by thefirst LED 910-1 being illuminated), and the maximum stimulation levelselectable by the patient remote 900 is 2.662 mA (represented by theseventh LED 910-7 being illuminated).

In an alternative exemplary embodiment, the pulse generator can beprogrammed to have a baseline stimulation of 2.0 mA with four selectablestimulation levels greater than the baseline stimulation level and twoselectable stimulation levels less than the baseline stimulation level,where each step of adjustment can be ten percent (10%) of the existingor current stimulation level. In such an embodiment, the baselinestimulation level of 2.0 mA is represented in the stimulation-leveldisplay 910 by the third LED 910-3 being illuminated, the minimumstimulation level selectable by the patient remote 900 is 1.62 mA(represented by the first LED 910-1 being illuminated), and the maximumstimulation level selectable by the patient remote 900 is 2.9282 mA(represented by the seventh LED 910-7 being illuminated).

Table 2 set forth below summarizes the functionality resulting fromactuation of each of the activation switch 904, the stimulation-increaseswitch 906, and the stimulation-decrease switch 908, which in someembodiments are in part dependent on the status mode (i.e., awake orasleep) of the patient remote 900. As noted above, when the patientremote 900 is in the asleep mode, both of the stimulation-increaseswitch 906 and the stimulation-decrease switch 908 are inactive.

TABLE 2 Patient Remote Control Elements and Functionality ControlPatient Remote Element Mode Action Function Activation Asleep Shortactuation Place Patient Remote in Awake Switch Mode; Communicate withNeurostimulation System; Display Current Stimulation Settings ofNeurostimulation System. Awake Short actuation Place Patient Remote inAsleep Mode. Stimulation- Awake Short actuation Increase StimulationLevel UP by Increase One Level; If Neurostimulation Switch System wasOFF, Turn Neurostimulation System ON at Stimulation Level 1. Longactuation Turn Neurostimulation System ON and Ramp UP to Stored PreviousStimulation Level. Stimulation- Awake Short actuation DecreaseStimulation Level DOWN Decrease by One Level; If Stimulation LevelSwitch is Decreased Below Stimulation Level 1, Turn NeurostimulationSystem OFF. Long actuation Turn Neurostimulation System OFF and StorePrevious Stimulation Level.

FIGS. 9-8 and 9-9 are schematic illustrations of a patient remote 900with a therapy-remaining display 912 showing levels of therapy remainingfor a neurostimulation system. The therapy-remaining display 912 can bean LED indicator capable of emitting one or more colors of light. InFIG. 9-8, the therapy-remaining display 912 is shown emitting a greenlight 913 g (as represented by the solid-line wavefront illustration).In FIG. 9-9, the therapy-remaining display 912 is shown emitting anamber light 913 a (as represented by the broken-line wavefrontillustration). In some embodiments, the therapy-remaining display 912can disposed on the exterior surface of the portable housing 902, suchas on the control surface 903. Further, the therapy-remaining display912 can illuminate with a constant (non-flashing) emission of light, orcan illuminate in a flashing or intermittent mode. In implementations ofthe patient remote 900 where the therapy-remaining display 912 is abi-color LED, the color of light emitted by the therapy-remainingdisplay 912 and whether the light is emitted as constant or flashing canprovide an observer with a qualitative indication of how much therapyand/or battery life is remaining in a neurostimulation system pulsegenerator.

In an exemplary implementation, the therapy-remaining display 912 canemit a green light 913 g when the pulse generator rechargeable batteryhas at least thirty percent (>30%) of its charge capacity remaining,which can corresponds to at least four (>4) days of nominal stimulationremaining in the neurostimulation system. Further in thisimplementation, the therapy-remaining display 912 can emit a constantamber light 913 a when the pulse generator battery has more than fifteenpercent (>15%) but less than thirty percent (<30%) of its chargecapacity remaining, which can corresponds to about two to four (2-4)days of nominal stimulation remaining in the neurostimulation system.The therapy-remaining display 912 emitting a constant amber light 913 acan be an indication to the patient that the pulse generator battery isrelatively low on charge and requires recharging within the subsequent2-4 days. Further in this implementation, the therapy-remaining display912 can emit a flashing amber light 913 a when the pulse generatorbattery has less than fifteen percent (<15%) its charge capacityremaining. The therapy-remaining display 912 emitting flashing amberlight 913 a can be an indication to the patient that the pulse generatorbattery is critically low on charge, requires immediate recharging, andthat the neurostimulation system may automatically turn off. Thetherapy-remaining display 912 can further indicate that the pulsegenerator battery is recharging, where in some aspects thetherapy-remaining display 912 can emit a flashing green light 913 g asthe pulse generator battery recharges.

The amount of charge capacity will vary from battery to battery for anypulse generator or neurostimulation system. In some embodiments, therechargeable battery can have a charge capacity such that 30% of thecharge capacity is about 3.55 Volts and 15% of the charge capacity isabout 3.45 Volts, where the therapy-remaining display 912 can emit aconstant or flashing green light 913 g or a constant or flashing amberlight 913 a as appropriate relative to such voltages.

The amount of therapy remaining for a neurostimulation system and pulsegenerator is dependent at least on the duration of usage of theneurostimulation system and the level of stimulation theneurostimulation system is instructed to deliver. Accordingly, aprocessor coupled to the pulse generator can calculate the amount oftherapy remaining in a pulse generator based on factors including, butnot limited to, the overall capacity of the pulse generator rechargeablebattery, the amount of time elapsed since the pulse generatorrechargeable battery was last recharged, the average stimulation levelat which the pulse generator is operated, the median stimulation levelat which the pulse generator is operated, the current voltage of thebattery, and the like. In some aspects, the therapy remaining and/orcharge capacity of the pulse generator rechargeable battery can becalculated according to one or more of stimulation amplitude,stimulation frequency, stimulation pulse width, stimulation cycling mode(e.g. duty cycle), and impedance. Based on this calculation, when thepatient remote 900 interrogates the neurostimulator and retrieves thestatus of the pulse generator, the therapy-remaining display 912 canilluminate to provide feedback to the patient indicative of the currentamount of therapy remaining in the pulse generator.

The visual indicators of the patient remote 900 can be augmented with ahaptic or vibratory feedback that punctuates adjustments to stimulationlevel, where a vibrating element (e.g., a motor, a piezoelectric, etc.)is disposed within the interior of the portable housing 902. Thevibrating element can be configured to activate when the pulse generatorconfirms that an instruction from the patient remote 900 has beenreceived and executed. Such commands from the patient remote caninclude, but are not limited to, turning on the pulse generator, turningoff the pulse generator increasing the stimulation level of the pulsegenerator, or decreasing the stimulation level of the pulse generator.The vibration element can also be configured to activate for situationsincluding, but not limited to, the patient remote 900 switching from theasleep mode to the awake mode or providing a warning that therechargeable pulse generator battery has a low charge.

Table 3 set forth below summarizes the feedback indicators provided inembodiments of the patient remote 900, such as the stimulation-leveldisplay 910, the therapy-remaining display 912, and the vibrationelement, and interpretations of the feedback from the indicators.

TABLE 3 Patient Remote Indicators and Feedback Patient Remote IndicatorsStructure Status Feedback Stimulation- 7 LED array Remote The LED arraydisplays a “scanning” Level Display transition from sequence. asleepmode to awake mode. Remote in awake A number of LEDs are Illuminatedmode. Corresponding to the Current Stimulation Level. Therapy- Bi-ColorLED Remote in awake Therapy-Remaining Display Remaining mode. IndicatesNeurostimulation System Display Battery Status (e.g., good charge, lowcharge, very low charge, charging) Haptic Vibration Motor Remote inawake Vibration when the Neurostimulation mode. System Confirms that aCommand from the Patient Remote has been Received and Executed.

The patient remote 900 can further include a fault condition indicator914, which can illuminate when either or both of the patient remote andthe pulse generator are in a fault condition. The fault conditionindicator 914 can be an LED, such as a white-light, red-light, or othercolored-light LED which can emit a constant or flashing light wheneither or both of the patient remote and the pulse generator are in afault condition. Problems with the neurostimulation system that cancause the fault condition indicator 914 to illuminate include, but arenot limited to, failure of the pulse generator to respond to commandsfrom the patient remote 900, a low charge for the battery operating thepatient remote 900, where fault conditions are of the type common toactive implantable devices, which for example may be one or more of lowpatient remote battery, patient remote software or hardware fault, pulsegenerator hardware or software fault, and impedance out of range.

In order to make the patient remote 900 a convenient fob device for apatient to carry and used, the portable housing 902 can have amechanical coupling structure 916 to attach the patient remote 900 witha key ring, karabiner, or other such mounting element. In variousaspects, the mechanical coupling structure 916 can be embedded in thestructure of the portable housing 902 or looped around a portion of theportable housing 902.

FIG. 10 is a functional block diagram of components of a patient remote1000. In the embodiment as illustrated, the patient remote 1000 enclosesa battery 1002, control electronics 1004, transmission circuitry 1006,and a bus structure 1008 to allow for communication and transmission ofpower between the components of the patient remote 1000. The patientremote also optionally includes a memory 1010 for storing of data, suchas the stimulation status of a linked neurostimulation system. Thecontrol electronics 1004 also includes locations where the controlelectronics 1004 can couple with an activation switch 1012, astimulation-increase switch 1014, and a stimulation-decrease switch1016. The bus 1008 can further communicate with a stimulation leveldisplay 1018, a therapy-remaining-display 1020, a vibration motor 1022,and a fault condition indicator 1024.

The optional memory 1010 of the patient remote 1000 can store a previousor last stimulation level at which a pulse generator (e.g., an IPG orEPG) paired to the patient remote 1000 was operating. In implementationsof the patient remote without an optional memory 1010, the previous orlast stimulation level at which a pulse generator paired to the patientremote 1000 was operating can be stored within data memory of the pulsegenerator, respectively. The status or condition of the pulse generatorcan be transmitted to the transmission circuitry 1006 of the patientremote 1000 upon interrogation of the pulse generator when the patientremote 1000 is triggered into an awake mode. The status or condition ofthe pulse generator, particularly the information of the previous orlast stimulation level, can be conveyed to the control electronic 1004of the patient remote to allow for control of the pulse generator viathe patient remote based upon the relevant stimulation level of thepulse generator. In many implementations, the transmission of databetween a pulse generator and the patient remote can be wireless, andcan further be set at a predetermined radio frequency (RF) for a pairedset of a patient remote and pulse generator.

In the foregoing specification, the invention is described withreference to specific embodiments thereof, but those skilled in the artwill recognize that the invention is not limited thereto. Variousfeatures and aspects of the above-described invention can be usedindividually or jointly. Further, the invention can be utilized in anynumber of environments and applications beyond those described hereinwithout departing from the broader spirit and scope of thespecification. The specification and drawings are, accordingly, to beregarded as illustrative rather than restrictive. It will be recognizedthat the terms “comprising,” “including,” and “having,” as used herein,are specifically intended to be read as open-ended terms of art.

What is claimed is:
 1. A patient remote configured to wirelessly controla nerve-stimulating pulse generator coupled to an implantable lead in apatient, the patient remote comprising: a portable housing configured tobe operable by a single hand of an operator; circuitry disposed withinthe portable housing, the circuitry configured to wirelessly communicatewith the pulse generator; an activation button disposed on an exteriorsurface of the portable housing and coupled to the circuitry, whereinthe circuitry is further configured to reconfigure the patient remotebetween an awake mode and an asleep mode when the activation button isactuated; and a stimulation-increase button disposed on the exteriorsurface of the portable housing, the stimulation-increase button coupledto the circuitry, wherein when the stimulation-increase button isactuated the circuitry is further configured to wirelessly sendinstruction signals to the pulse generator to increase a stimulationlevel of the pulse generator; wherein when the patient remote is in theawake mode, actuation of the stimulation-increase button for a firstperiod of time causes the circuitry to communicate the instructionsignals to the pulse generator to increase the stimulation level of thepulse generator, and actuation of the stimulation-increase button for asecond period of time causes the circuitry to communicate theinstruction signals to the pulse generator to restore the pulsegenerator to a last stored stimulation level.
 2. The patient remote ofclaim 1, wherein first period of time comprises a period of time lessthan a threshold period and the second period of time comprises a periodof time greater than the threshold, wherein actuation of thestimulation-increase button for the second period of time ramps thestimulation level to the last stored stimulation level, and wherein thethreshold period is three seconds or more.
 3. The patient remote ofclaim 1, further comprising a memory element coupled to the circuitry,and further comprising a stimulation-decrease button disposed on theexterior surface of the portable housing and coupled to the circuitry soas to wirelessly decrease the stimulation level of the pulse generator,wherein when the patient remote is in the awake mode, actuation of thestimulation-decrease button for the first period of time decreases thestimulation level, and actuation of the stimulation-decrease button forthe second period of time stores the stimulation level in the memoryelement for subsequent use as the stored stimulation level and turns offthe stimulation by the pulse generator.
 4. The patient remote of claim3, wherein the circuitry is configured so that repeated actuation of thestimulation-increase button can incrementally increase the stimulationlevel no more than four stimulation levels above a nominal stimulationlevel and repeated actuation of the stimulation-decrease button canincrementally decrease the stimulation level down respectively no morethan three stimulation levels below the nominal stimulation level. 5.The patient remote of claim 3, wherein each stimulation level increaseor stimulation level decrease of the pulse generator comprises more than5 percent of a nominal stimulation level or a current stimulation level.6. The patient remote of claim 1, further comprising a stimulation-leveldisplay disposed on the exterior surface of the portable housing, thestimulation-level display and circuitry configured to indicate a currentstimulation level of the pulse generator when the activation button ofthe patient remote is switched from the asleep mode to the awake mode.7. The patient remote of claim 6, wherein the stimulation-level displaycomprises a plurality of light emitting diodes, wherein a number ofilluminated light emitting diodes indicates the current stimulationlevel of the pulse generator.
 8. The patient remote of claim 6, whereinthe stimulation-level display comprises at least seven light emittingdiodes of at least three or four differing sizes, wherein a nominalstimulation level corresponds to illumination of the first three or fourlight emitting diodes.
 9. The patient remote of claim 1, furthercomprising a therapy-remaining display on the exterior surface of theportable housing, the therapy-remaining display and circuitry configuredto indicate therapy remaining status of the pulse generator based on atleast a charge or voltage remaining in a battery of the pulse generatorand stimulation use by the patient.
 10. The patient remote of claim 9,wherein the therapy-remaining display comprises a light emitting diodehaving a plurality of contrasting display modes, the display modescomprising a plurality of colors or flashing and non-flashingillumination or both and sufficient to indicate if the pulse generatorneeds re-charging, is charging, or has sufficient charge for at least athreshold number of days of stimulation.
 11. The patient remote of claim10, wherein the therapy-remaining display light emitting diodeilluminates with a non-flashing green color to indicate at least 4 daysof therapy remaining, illuminates with a non-flashing amber color toindicate 2-4 days of therapy remaining, and illuminates with a flashingamber color to indicate less than 2 days of therapy remaining.
 12. Thepatient remote of claim 1, further comprising an automatic faultcondition indicator disposed on the exterior surface of the portablehousing configured to provide an alert if the pulse generator is in afault condition.
 13. The patient remote of claim 1, further comprising ahaptic indicator coupled to the portable housing and configured tovibrate when a command from the patient remote has been executed by thepulse generator.
 14. The patient remote of claim 1, wherein the patientremote is configured to wirelessly control either an external orimplantable nerve-stimulating pulse generator and wherein the externalor implantable nerve-stimulating pulse generator includes an implantablelead that comprises at least one electrode configured for insertion intoa foramen of a sacrum near a sacral nerve.
 15. The patient remote ofclaim 1, wherein the circuitry is configured to send instruction signalssuch that the stimulation level of the pulse generator is incrementallyincreased or decreased by a predetermined amount of a maximumstimulation level, a nominal stimulation level, or a current stimulationlevel of the pulse generator.
 16. The patient remote of claim 15,wherein the predetermined amount is a percentage between five and twentypercent of: a maximum stimulation level, a nominal stimulation level, ora current stimulation level of the pulse generator.
 17. The patientremote of claim 15, wherein the maximum stimulation level is setaccording to incremental step-sizes, corresponding to a comfort level ofa patient.
 18. The patient remote of claim 1, wherein the patient remotemaintains the stimulation level after the stimulation level of the pulsegenerator is set, until the patient remote is operated by the operatorto terminate or change stimulation by the pulse generator.
 19. Thepatient remote of claim 1, wherein the patient remote circuitry isconfigured to pair with and communicate only and/or directly with thepulse generator.